Removes the GTK2 build requirement. A little sloppy in places,
will be cleaned up over the next couple of weeks. Based on a
patch posted to Bugzilla here:

https://bugzilla.mozilla.org/show_bug.cgi?id=1663588

---
diff --git a/browser/installer/package-manifest.in b/browser/installer/package-manifest.in
index 75c79a7168..ee9cd18fe8 100644
--- a/browser/installer/package-manifest.in
+++ b/browser/installer/package-manifest.in
@@ -107,7 +107,6 @@
 #endif
 #ifdef MOZ_GTK
 @BINPATH@/@DLL_PREFIX@mozgtk@DLL_SUFFIX@
-@BINPATH@/gtk2/@DLL_PREFIX@mozgtk@DLL_SUFFIX@
 #ifdef MOZ_WAYLAND
 @BINPATH@/@DLL_PREFIX@mozwayland@DLL_SUFFIX@
 #endif
diff --git a/dom/moz.build b/dom/moz.build
index d34d8a7f75..4e5648089b 100644
--- a/dom/moz.build
+++ b/dom/moz.build
@@ -119,7 +119,7 @@ TEST_DIRS += [
     'imptests',
 ]

-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk', 'cocoa', 'windows'):
+if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('cocoa', 'windows'):
     TEST_DIRS += ['plugins/test']

 SPHINX_TREES['/dom'] = 'docs'
diff --git a/dom/plugins/base/npapi.h b/dom/plugins/base/npapi.h
index d6b189baef..adc98f975c 100644
--- a/dom/plugins/base/npapi.h
+++ b/dom/plugins/base/npapi.h
@@ -41,9 +41,9 @@
 #  endif
 #endif

-#if defined(XP_UNIX)
+#if defined(MOZ_X11)
 #  include <stdio.h>
-#  if defined(MOZ_X11)
+#  if 0
 #    include <X11/Xlib.h>
 #    include <X11/Xutil.h>
 #    include "X11UndefineNone.h"
@@ -211,7 +211,7 @@ typedef struct _NPAsyncSurface {
 /* Exact meaning must be spec'd in event model. */
 #  define kNPEventStartIME 2

-#  if defined(XP_UNIX)
+#  if 0
 /*
  * Unix specific structures and definitions
  */
@@ -229,7 +229,7 @@ typedef struct {

 typedef struct {
   int32_t type;
-#    if defined(MOZ_X11)
+#    if 0
   Display* display;
   Visual* visual;
   Colormap colormap;
@@ -291,7 +291,7 @@ typedef enum {
   ,
   NPDrawingModelSyncWin = 5
 #  endif
-#  if defined(MOZ_X11)
+#  if 0
   ,
   NPDrawingModelSyncX = 6
 #  endif
@@ -330,7 +330,7 @@ typedef enum {
  *   gcc 3.x generated vtables on UNIX and OSX are incompatible with
  *   previous compilers.
  */
-#  if (defined(XP_UNIX) && defined(__GNUC__) && (__GNUC__ >= 3))
+#  if 0
 #    define _NP_ABI_MIXIN_FOR_GCC3 NP_ABI_GCC3_MASK
 #  else
 #    define _NP_ABI_MIXIN_FOR_GCC3 0
@@ -530,7 +530,7 @@ typedef struct _NPWindow {
   uint32_t width; /* Maximum window size */
   uint32_t height;
   NPRect clipRect; /* Clipping rectangle in port coordinates */
-#  if (defined(XP_UNIX) || defined(XP_SYMBIAN)) && !defined(XP_MACOSX)
+#  if (defined(XP_SYMBIAN)) && !defined(XP_MACOSX)
   void* ws_info;     /* Platform-dependent additional data */
 #  endif             /* XP_UNIX */
   NPWindowType type; /* Is this a window or a drawable? */
@@ -583,7 +583,7 @@ typedef struct _NPEvent {
   uintptr_t wParam;
   intptr_t lParam;
 } NPEvent;
-#  elif defined(XP_UNIX) && defined(MOZ_X11)
+#  elif 0
 typedef XEvent NPEvent;
 #  else
 typedef void* NPEvent;
@@ -597,7 +597,7 @@ typedef RgnHandle NPQDRegion;
 typedef CGPathRef NPCGRegion;
 #  elif defined(XP_WIN)
 typedef HRGN NPRegion;
-#  elif defined(XP_UNIX) && defined(MOZ_X11)
+#  elif 0
 typedef Region NPRegion;
 #  elif defined(XP_SYMBIAN)
 typedef QRegion* NPRegion;
@@ -828,7 +828,7 @@ extern "C" {

 /* NPP_* functions are provided by the plugin and called by the navigator. */

-#  if defined(XP_UNIX)
+#  if 0
 const char* NPP_GetMIMEDescription(void);
 #  endif

diff --git a/dom/plugins/base/nsNPAPIPlugin.cpp b/dom/plugins/base/nsNPAPIPlugin.cpp
index 829db86079..9870c6a487 100644
--- a/dom/plugins/base/nsNPAPIPlugin.cpp
+++ b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -55,7 +55,7 @@
 #endif

 // needed for nppdf plugin
-#if (MOZ_WIDGET_GTK)
+#if 0
 #  include <gdk/gdk.h>
 #  include <gdk/gdkx.h>
 #endif
@@ -74,7 +74,7 @@ using mozilla::PluginLibrary;
 using mozilla::plugins::PluginModuleChromeParent;
 using mozilla::plugins::PluginModuleContentParent;

-#ifdef MOZ_X11
+#if 0
 #  include "mozilla/X11Util.h"
 #endif

@@ -1224,9 +1224,9 @@ NPError _getvalue(NPP npp, NPNVariable variable, void* result) {
   // Cast NPNVariable enum to int to avoid warnings about including switch
   // cases for android_npapi.h's non-standard ANPInterface values.
   switch (static_cast<int>(variable)) {
-#if defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
     case NPNVxDisplay: {
-#  if defined(MOZ_X11)
+#  if 0
       if (npp) {
         nsNPAPIPluginInstance* inst = (nsNPAPIPluginInstance*)npp->ndata;
         bool windowless = false;
@@ -1260,7 +1260,7 @@ NPError _getvalue(NPP npp, NPNVariable variable, void* result) {
       return NPERR_GENERIC_ERROR;
 #endif

-#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+#if defined(XP_WIN)
     case NPNVnetscapeWindow: {
       if (!npp || !npp->ndata) return NPERR_INVALID_INSTANCE_ERROR;

@@ -1302,7 +1302,7 @@ NPError _getvalue(NPP npp, NPNVariable variable, void* result) {
     }

     case NPNVToolkit: {
-#ifdef MOZ_WIDGET_GTK
+#if 0
       *((NPNToolkitType*)result) = NPNVGtk2;
 #endif

@@ -1312,7 +1312,7 @@ NPError _getvalue(NPP npp, NPNVariable variable, void* result) {
     }

     case NPNVSupportsXEmbedBool: {
-#ifdef MOZ_WIDGET_GTK
+#if 0
       *(NPBool*)result = true;
 #else
       *(NPBool*)result = false;
@@ -1333,8 +1333,7 @@ NPError _getvalue(NPP npp, NPNVariable variable, void* result) {
     }

     case NPNVSupportsWindowless: {
-#if defined(XP_WIN) || defined(XP_MACOSX) || \
-    (defined(MOZ_X11) && defined(MOZ_WIDGET_GTK))
+#if defined(XP_WIN) || defined(XP_MACOSX)
       *(NPBool*)result = true;
 #else
       *(NPBool*)result = false;
diff --git a/dom/plugins/base/nsNPAPIPluginInstance.cpp b/dom/plugins/base/nsNPAPIPluginInstance.cpp
index c011cd038d..1d5224a45d 100644
--- a/dom/plugins/base/nsNPAPIPluginInstance.cpp
+++ b/dom/plugins/base/nsNPAPIPluginInstance.cpp
@@ -316,7 +316,7 @@ nsresult nsNPAPIPluginInstance::SetWindow(NPWindow* window) {
   // NPAPI plugins don't want a SetWindow(nullptr).
   if (!window || RUNNING != mRunning) return NS_OK;

-#if MOZ_WIDGET_GTK
+#if 0
   // bug 108347, flash plugin on linux doesn't like window->width <= 0
   return NS_OK;
 #endif
diff --git a/dom/plugins/base/nsNPAPIPluginInstance.h b/dom/plugins/base/nsNPAPIPluginInstance.h
index 1ca2569ae8..2977f96902 100644
--- a/dom/plugins/base/nsNPAPIPluginInstance.h
+++ b/dom/plugins/base/nsNPAPIPluginInstance.h
@@ -38,7 +38,7 @@ class Element;

 #if defined(OS_WIN)
 const NPDrawingModel kDefaultDrawingModel = NPDrawingModelSyncWin;
-#elif defined(MOZ_X11)
+#elif 0
 const NPDrawingModel kDefaultDrawingModel = NPDrawingModelSyncX;
 #elif defined(XP_MACOSX)
 #  ifndef NP_NO_QUICKDRAW
diff --git a/dom/plugins/base/nsPluginHost.cpp b/dom/plugins/base/nsPluginHost.cpp
index 8edea3aa14..66dd9a1973 100644
--- a/dom/plugins/base/nsPluginHost.cpp
+++ b/dom/plugins/base/nsPluginHost.cpp
@@ -85,7 +85,7 @@
 #  include "windows.h"
 #  include "winbase.h"
 #endif
-#if (MOZ_WIDGET_GTK)
+#if 0
 #  include <gdk/gdk.h>
 #  include <gdk/gdkx.h>
 #endif
@@ -278,7 +278,7 @@ nsPluginHost::nsPluginHost()
   }

   bool waylandBackend = false;
-#if MOZ_WIDGET_GTK
+#if 0
   GdkDisplay* display = gdk_display_get_default();
   if (display) {
     waylandBackend = !GDK_IS_X11_DISPLAY(display);
diff --git a/dom/plugins/base/nsPluginInstanceOwner.cpp b/dom/plugins/base/nsPluginInstanceOwner.cpp
index 23053888d4..0e6376e758 100644
--- a/dom/plugins/base/nsPluginInstanceOwner.cpp
+++ b/dom/plugins/base/nsPluginInstanceOwner.cpp
@@ -4,7 +4,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

-#ifdef MOZ_X11
+#if 0
 #  include <cairo-xlib.h>
 #  include "gfxXlibSurface.h"
 /* X headers suck */
@@ -75,7 +75,7 @@ static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
 #  include "ComplexTextInputPanel.h"
 #endif

-#ifdef MOZ_WIDGET_GTK
+#if 0
 #  include <gdk/gdk.h>
 #  include <gtk/gtk.h>
 #endif
@@ -621,7 +621,7 @@ NS_IMETHODIMP nsPluginInstanceOwner::GetNetscapeWindow(void* value) {
   }

   return NS_OK;
-#elif defined(MOZ_WIDGET_GTK) && defined(MOZ_X11)
+#elif 0
   // X11 window managers want the toplevel window for WM_TRANSIENT_FOR.
   nsIWidget* win = mPluginFrame->GetNearestWidget();
   if (!win) return NS_ERROR_FAILURE;
@@ -1743,7 +1743,7 @@ nsresult nsPluginInstanceOwner::HandleEvent(Event* aEvent) {
   return NS_OK;
 }

-#ifdef MOZ_X11
+#if 0
 static unsigned int XInputEventState(const WidgetInputEvent& anEvent) {
   unsigned int state = 0;
   if (anEvent.IsShift()) state |= ShiftMask;
@@ -2224,7 +2224,7 @@ nsEventStatus nsPluginInstanceOwner::ProcessEvent(
   }
 #endif

-#ifdef MOZ_X11
+#if 0
   // this code supports windowless plugins
   nsIWidget* widget = anEvent.mWidget;
   XEvent pluginEvent = XEvent();
@@ -2255,7 +2255,7 @@ nsEventStatus nsPluginInstanceOwner::ProcessEvent(
       if (widget) {
         rootPoint = anEvent.mRefPoint + widget->WidgetToScreenOffset();
       }
-#  ifdef MOZ_WIDGET_GTK
+#  if 0
       Window root = GDK_ROOT_WINDOW();
 #  else
       Window root = X11None;  // Could XQueryTree, but this is not important.
@@ -2333,7 +2333,7 @@ nsEventStatus nsPluginInstanceOwner::ProcessEvent(
     case eKeyboardEventClass:
       if (anEvent.mPluginEvent) {
         XKeyEvent& event = pluginEvent.xkey;
-#  ifdef MOZ_WIDGET_GTK
+#  if 0
         event.root = GDK_ROOT_WINDOW();
         event.time = anEvent.mTime;
         const GdkEventKey* gdkEvent =
@@ -2517,7 +2517,7 @@ void nsPluginInstanceOwner::Paint(const RECT& aDirty, HDC aDC) {
 }
 #endif

-#if defined(MOZ_X11)
+#if 0
 void nsPluginInstanceOwner::Paint(gfxContext* aContext,
                                   const gfxRect& aFrameRect,
                                   const gfxRect& aDirtyRect) {
@@ -2651,7 +2651,7 @@ nsresult nsPluginInstanceOwner::Renderer::DrawWithXlib(

   NPSetWindowCallbackStruct* ws_info =
       static_cast<NPSetWindowCallbackStruct*>(mWindow->ws_info);
-#  ifdef MOZ_X11
+#  if 0
   if (ws_info->visual != visual || ws_info->colormap != colormap) {
     ws_info->visual = visual;
     ws_info->colormap = colormap;
@@ -2863,7 +2863,7 @@ NS_IMETHODIMP nsPluginInstanceOwner::CreateWidget(void) {
     // passing HDC till paint event when it is really
     // needed. Change spec?
     mPluginWindow->window = nullptr;
-#ifdef MOZ_X11
+#if 0
     // Fill in the display field.
     NPSetWindowCallbackStruct* ws_info =
         static_cast<NPSetWindowCallbackStruct*>(mPluginWindow->ws_info);
diff --git a/dom/plugins/base/nsPluginInstanceOwner.h b/dom/plugins/base/nsPluginInstanceOwner.h
index fbb87b6113..e5e4b86159 100644
--- a/dom/plugins/base/nsPluginInstanceOwner.h
+++ b/dom/plugins/base/nsPluginInstanceOwner.h
@@ -31,7 +31,7 @@ class nsPluginDOMContextMenuListener;
 class nsPluginFrame;
 class nsDisplayListBuilder;

-#if defined(MOZ_X11)
+#if 0
 class gfxContext;
 #endif

@@ -48,7 +48,7 @@ class PuppetWidget;

 using mozilla::widget::PuppetWidget;

-#ifdef MOZ_X11
+#if 0
 #  include "gfxXlibNativeRenderer.h"
 #endif

@@ -112,7 +112,7 @@ class nsPluginInstanceOwner final : public nsIPluginInstanceOwner,
   void Paint(const gfxRect& aDirtyRect, CGContextRef cgContext);
   void RenderCoreAnimation(CGContextRef aCGContext, int aWidth, int aHeight);
   void DoCocoaEventDrawRect(const gfxRect& aDrawRect, CGContextRef cgContext);
-#elif defined(MOZ_X11)
+#elif 0
   void Paint(gfxContext* aContext, const gfxRect& aFrameRect,
              const gfxRect& aDirtyRect);
 #endif
@@ -193,7 +193,7 @@ class nsPluginInstanceOwner final : public nsIPluginInstanceOwner,
     return "";
   }

-#ifdef MOZ_X11
+#if 0
   void GetPluginDescription(nsACString& aDescription) {
     aDescription.Truncate();
     if (mInstance && mPluginHost) {
@@ -214,7 +214,7 @@ class nsPluginInstanceOwner final : public nsIPluginInstanceOwner,
     return mPluginWindow->type == NPWindowTypeDrawable &&
            (MatchPluginName("Shockwave Flash") ||
             MatchPluginName("Test Plug-in"));
-#elif defined(MOZ_X11) || defined(XP_MACOSX)
+#elif defined(XP_MACOSX)
     return true;
 #else
     return false;
@@ -325,7 +325,7 @@ class nsPluginInstanceOwner final : public nsIPluginInstanceOwner,
   uint32_t mLastEventloopNestingLevel;
   bool mContentFocused;
   bool mWidgetVisible;  // used on Mac to store our widget's visible state
-#ifdef MOZ_X11
+#if 0
   // Used with windowless plugins only, initialized in CreateWidget().
   bool mFlash10Quirks;
 #endif
@@ -371,7 +371,7 @@ class nsPluginInstanceOwner final : public nsIPluginInstanceOwner,

   int mLastMouseDownButtonType;

-#ifdef MOZ_X11
+#if 0
   class Renderer : public gfxXlibNativeRenderer {
    public:
     Renderer(NPWindow* aWindow, nsPluginInstanceOwner* aInstanceOwner,
diff --git a/dom/plugins/base/nsPluginNativeWindow.cpp b/dom/plugins/base/nsPluginNativeWindow.cpp
index 6aea8d28fc..f4f2ac36b7 100644
--- a/dom/plugins/base/nsPluginNativeWindow.cpp
+++ b/dom/plugins/base/nsPluginNativeWindow.cpp
@@ -17,7 +17,7 @@ class nsPluginNativeWindowImpl : public nsPluginNativeWindow {
   nsPluginNativeWindowImpl();
   virtual ~nsPluginNativeWindowImpl();

-#ifdef MOZ_WIDGET_GTK
+#if 0
   NPSetWindowCallbackStruct mWsInfo;
 #endif
 };
@@ -32,14 +32,14 @@ nsPluginNativeWindowImpl::nsPluginNativeWindowImpl() : nsPluginNativeWindow() {
   memset(&clipRect, 0, sizeof(clipRect));
   type = NPWindowTypeWindow;

-#ifdef MOZ_WIDGET_GTK
+#if 0
   ws_info = &mWsInfo;
   mWsInfo.type = 0;
   mWsInfo.display = nullptr;
   mWsInfo.visual = nullptr;
   mWsInfo.colormap = 0;
   mWsInfo.depth = 0;
-#elif defined(XP_UNIX) && !defined(XP_MACOSX)
+#elif 0
   ws_info = nullptr;
 #endif
 }
diff --git a/dom/plugins/ipc/NPEventUnix.h b/dom/plugins/ipc/NPEventUnix.h
index 55494b4d8c..822d3b88e3 100644
--- a/dom/plugins/ipc/NPEventUnix.h
+++ b/dom/plugins/ipc/NPEventUnix.h
@@ -9,7 +9,7 @@

 #include "npapi.h"

-#ifdef MOZ_X11
+#if 0
 #  include "mozilla/X11Util.h"
 #endif

@@ -59,7 +59,7 @@ struct ParamTraits<mozilla::plugins::NPRemoteEvent>  // synonym for XEvent
       return false;
     }

-#ifdef MOZ_X11
+#if 0
     SetXDisplay(aResult->event);
 #endif
     return true;
@@ -70,7 +70,7 @@ struct ParamTraits<mozilla::plugins::NPRemoteEvent>  // synonym for XEvent
     aLog->append(L"(XEvent)");
   }

-#ifdef MOZ_X11
+#if 0
  private:
   static void SetXDisplay(XEvent& ev) {
     Display* display = mozilla::DefaultXDisplay();
diff --git a/dom/plugins/ipc/PluginInstanceChild.cpp b/dom/plugins/ipc/PluginInstanceChild.cpp
index 9d6c04dced..b163c4c548 100644
--- a/dom/plugins/ipc/PluginInstanceChild.cpp
+++ b/dom/plugins/ipc/PluginInstanceChild.cpp
@@ -15,7 +15,7 @@
 #include "gfx2DGlue.h"
 #include "nsNPAPIPluginInstance.h"
 #include "mozilla/gfx/2D.h"
-#ifdef MOZ_X11
+#if 0
 #  include "gfxXlibSurface.h"
 #endif
 #ifdef XP_WIN
@@ -44,7 +44,7 @@ using namespace mozilla::layers;
 using namespace mozilla::gfx;
 using namespace mozilla::widget;

-#ifdef MOZ_WIDGET_GTK
+#if 0

 #  include <gtk/gtk.h>
 #  include <gdk/gdkx.h>
@@ -188,10 +188,10 @@ PluginInstanceChild::PluginInstanceChild(const NPPluginFuncs* aPluginIface,
   mWindow.type = NPWindowTypeWindow;
   mData.ndata = (void*)this;
   mData.pdata = nullptr;
-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
   mWindow.ws_info = &mWsInfo;
   memset(&mWsInfo, 0, sizeof(mWsInfo));
-#  ifdef MOZ_WIDGET_GTK
+#  if 1
   mWsInfo.display = nullptr;
 #  else
   mWsInfo.display = DefaultXDisplay();
@@ -356,7 +356,7 @@ NPError PluginInstanceChild::NPN_GetValue(NPNVariable aVar, void* aValue) {
   AutoStackHelper guard(this);

   switch (aVar) {
-#if defined(MOZ_X11)
+#if 0
     case NPNVToolkit:
       *((NPNToolkitType*)aValue) = NPNVGtk2;
       return NPERR_NO_ERROR;
@@ -428,7 +428,7 @@ NPError PluginInstanceChild::NPN_GetValue(NPNVariable aVar, void* aValue) {
         *static_cast<HWND*>(aValue) = mPluginWindowHWND;
         return NPERR_NO_ERROR;
       }
-#elif defined(MOZ_X11)
+#elif 0
       NPError result;
       CallNPN_GetValue_NPNVnetscapeWindow(static_cast<XID*>(aValue), &result);
       return result;
@@ -842,7 +842,7 @@ mozilla::ipc::IPCResult PluginInstanceChild::AnswerNPP_HandleEvent(
   AssertPluginThread();
   AutoStackHelper guard(this);

-#if defined(MOZ_X11) && defined(DEBUG)
+#if 0
   if (GraphicsExpose == event.event.type)
     PLUGIN_LOG_DEBUG(
         ("  received drawable 0x%lx\n", event.event.xgraphicsexpose.drawable));
@@ -899,7 +899,7 @@ mozilla::ipc::IPCResult PluginInstanceChild::AnswerNPP_HandleEvent(
   }
 #endif

-#ifdef MOZ_X11
+#if 0
   if (GraphicsExpose == event.event.type) {
     // Make sure the X server completes the drawing before the parent
     // draws on top and destroys the Drawable.
@@ -1154,7 +1154,7 @@ mozilla::ipc::IPCResult PluginInstanceChild::AnswerNPP_SetWindow(
   AssertPluginThread();
   AutoStackHelper guard(this);

-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
   NS_ASSERTION(mWsInfo.display, "We should have a valid display!");

   // The minimum info is sent over IPC to allow this
@@ -1250,14 +1250,14 @@ mozilla::ipc::IPCResult PluginInstanceChild::AnswerNPP_SetWindow(
 #elif defined(MOZ_WIDGET_UIKIT)
   // Don't care
 #else
-#  error Implement me for your OS
+//#  error Implement me for your OS
 #endif

   return IPC_OK();
 }

 bool PluginInstanceChild::Initialize() {
-#ifdef MOZ_WIDGET_GTK
+#if 0
   if (mWsInfo.display) {
     // Already initialized
     return true;
@@ -2870,7 +2870,7 @@ bool PluginInstanceChild::CreateOptSurface(void) {
                               ? SurfaceFormat::A8R8G8B8_UINT32
                               : SurfaceFormat::X8R8G8B8_UINT32;

-#ifdef MOZ_X11
+#if 0
   Display* dpy = mWsInfo.display;
   Screen* screen = DefaultScreenOfDisplay(dpy);
   if (format == SurfaceFormat::X8R8G8B8_UINT32 &&
@@ -2926,7 +2926,7 @@ bool PluginInstanceChild::MaybeCreatePlatformHelperSurface(void) {
     return false;
   }

-#ifdef MOZ_X11
+#if 0
   bool supportNonDefaultVisual = false;
   Screen* screen = DefaultScreenOfDisplay(mWsInfo.display);
   Visual* defaultVisual = DefaultVisualOfScreen(screen);
@@ -3078,12 +3078,12 @@ bool PluginInstanceChild::EnsureCurrentBuffer(void) {
 }

 void PluginInstanceChild::UpdateWindowAttributes(bool aForceSetWindow) {
-#if defined(MOZ_X11) || defined(XP_WIN)
+#if 0
   RefPtr<gfxASurface> curSurface =
       mHelperSurface ? mHelperSurface : mCurrentSurface;
 #endif  // Only used within MOZ_X11 or XP_WIN blocks. Unused variable otherwise
   bool needWindowUpdate = aForceSetWindow;
-#ifdef MOZ_X11
+#if 0
   Visual* visual = nullptr;
   Colormap colormap = 0;
   if (curSurface && curSurface->GetType() == gfxSurfaceType::Xlib) {
@@ -3182,7 +3182,7 @@ void PluginInstanceChild::PaintRectToPlatformSurface(const nsIntRect& aRect,
   // We should not send an async surface if we're using direct rendering.
   MOZ_ASSERT(!IsUsingDirectDrawing());

-#ifdef MOZ_X11
+#if 0
   {
     NS_ASSERTION(aSurface->GetType() == gfxSurfaceType::Xlib,
                  "Non supported platform surface type");
@@ -3230,7 +3230,7 @@ void PluginInstanceChild::PaintRectToSurface(const nsIntRect& aRect,
   // Render using temporary X surface, with copy to image surface
   nsIntRect plPaintRect(aRect);
   RefPtr<gfxASurface> renderSurface = aSurface;
-#ifdef MOZ_X11
+#if 0
   if (mIsTransparent && (GetQuirks() & QUIRK_FLASH_EXPOSE_COORD_TRANSLATION)) {
     // Work around a bug in Flash up to 10.1 d51 at least, where expose event
     // top left coordinates within the plugin-rect and not at the drawable
@@ -3573,7 +3573,7 @@ bool PluginInstanceChild::ShowPluginFrame() {
   NPRect r = {(uint16_t)rect.y, (uint16_t)rect.x, (uint16_t)rect.YMost(),
               (uint16_t)rect.XMost()};
   SurfaceDescriptor currSurf;
-#ifdef MOZ_X11
+#if 0
   if (mCurrentSurface->GetType() == gfxSurfaceType::Xlib) {
     gfxXlibSurface* xsurf = static_cast<gfxXlibSurface*>(mCurrentSurface.get());
     currSurf = SurfaceDescriptorX11(xsurf);
@@ -3621,7 +3621,7 @@ bool PluginInstanceChild::ReadbackDifferenceRect(const nsIntRect& rect) {

     // We can read safely from XSurface,SharedDIBSurface and Unsafe
     // SharedMemory, because PluginHost is not able to modify that surface
-#if defined(MOZ_X11)
+#if 0
   if (mBackSurface->GetType() != gfxSurfaceType::Xlib &&
       !gfxSharedImageSurface::IsSharedImage(mBackSurface))
     return false;
@@ -3629,7 +3629,7 @@ bool PluginInstanceChild::ReadbackDifferenceRect(const nsIntRect& rect) {
   if (!SharedDIBSurface::IsSharedDIBSurface(mBackSurface)) return false;
 #endif

-#if defined(MOZ_X11) || defined(XP_WIN)
+#if 0
   if (mCurrentSurface->GetContentType() != mBackSurface->GetContentType())
     return false;

@@ -3747,7 +3747,7 @@ mozilla::ipc::IPCResult PluginInstanceChild::RecvUpdateBackground(
   if (!mBackground) {
     // XXX refactor me
     switch (aBackground.type()) {
-#ifdef MOZ_X11
+#if 0
       case SurfaceDescriptor::TSurfaceDescriptorX11: {
         mBackground = aBackground.get_SurfaceDescriptorX11().OpenForeign();
         break;
diff --git a/dom/plugins/ipc/PluginInstanceChild.h b/dom/plugins/ipc/PluginInstanceChild.h
index 479c060f91..a00c1229aa 100644
--- a/dom/plugins/ipc/PluginInstanceChild.h
+++ b/dom/plugins/ipc/PluginInstanceChild.h
@@ -363,7 +363,7 @@ class PluginInstanceChild : public PPluginInstanceChild {
   PluginScriptableObjectChild* mCachedWindowActor;
   PluginScriptableObjectChild* mCachedElementActor;

-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
   NPSetWindowCallbackStruct mWsInfo;
 #elif defined(OS_WIN)
   HWND mPluginWindowHWND;
diff --git a/dom/plugins/ipc/PluginInstanceParent.cpp b/dom/plugins/ipc/PluginInstanceParent.cpp
index 802bba769a..a11b7497e3 100644
--- a/dom/plugins/ipc/PluginInstanceParent.cpp
+++ b/dom/plugins/ipc/PluginInstanceParent.cpp
@@ -25,7 +25,7 @@
 #include "nsNPAPIPluginInstance.h"
 #include "nsPluginInstanceOwner.h"
 #include "nsFocusManager.h"
-#ifdef MOZ_X11
+#if 0
 #  include "gfxXlibSurface.h"
 #endif
 #include "gfxUtils.h"
@@ -61,7 +61,7 @@
 #  include "GPUVideoImage.h"
 #  include "mozilla/layers/SynchronousTask.h"
 extern const wchar_t* kFlashFullscreenClass;
-#elif defined(MOZ_WIDGET_GTK)
+#elif 0
 #  include "mozilla/dom/ContentChild.h"
 #  include <gdk/gdk.h>
 #elif defined(XP_MACOSX)
@@ -182,7 +182,7 @@ void PluginInstanceParent::ActorDestroy(ActorDestroyReason why) {
     if (mImageContainer) {
       mImageContainer->ClearAllImages();
     }
-#ifdef MOZ_X11
+#if 0
     FinishX(DefaultXDisplay());
 #endif
   }
@@ -227,7 +227,7 @@ PluginInstanceParent::AnswerNPN_GetValue_NPNVnetscapeWindow(
 #ifdef XP_WIN
   HWND id;
 #elif defined(MOZ_X11)
-  XID id;
+  int id;
 #elif defined(XP_DARWIN)
   intptr_t id;
 #elif defined(ANDROID)
@@ -405,7 +405,7 @@ PluginInstanceParent::AnswerNPN_SetValue_NPPVpluginDrawingModel(
     case NPDrawingModelAsyncWindowsDXGISurface:
       allowed = SupportsPluginDirectDXGISurfaceDrawing();
       break;
-#elif defined(MOZ_X11)
+#elif 0
     case NPDrawingModelSyncX:
       allowed = true;
       break;
@@ -968,7 +968,7 @@ mozilla::ipc::IPCResult PluginInstanceParent::RecvShow(
     return IPC_OK();
   }
 #endif
-#ifdef MOZ_X11
+#if 0
   else if (newSurface.type() == SurfaceDescriptor::TSurfaceDescriptorX11) {
     surface = newSurface.get_SurfaceDescriptorX11().OpenForeign();
   }
@@ -985,7 +985,7 @@ mozilla::ipc::IPCResult PluginInstanceParent::RecvShow(
     // This is the "old front buffer" we're about to hand back to
     // the plugin.  We might still have drawing operations
     // referencing it.
-#ifdef MOZ_X11
+#if 0
     if (mFrontSurface->GetType() == gfxSurfaceType::Xlib) {
       // Finish with the surface and XSync here to ensure the server has
       // finished operations on the surface before the plugin starts
@@ -1224,7 +1224,7 @@ nsresult PluginInstanceParent::EndUpdateBackground(const nsIntRect& aRect) {
       ("[InstanceParent][%p] EndUpdateBackground for <x=%d,y=%d, w=%d,h=%d>",
        this, aRect.x, aRect.y, aRect.width, aRect.height));

-#ifdef MOZ_X11
+#if 0
   // Have to XSync here to avoid the plugin trying to draw with this
   // surface racing with its creation in the X server.  We also want
   // to avoid the plugin drawing onto stale pixels, then handing us
@@ -1270,7 +1270,7 @@ bool PluginInstanceParent::CreateBackground(const nsIntSize& aSize) {

   // XXX refactor me

-#if defined(MOZ_X11)
+#if 0
   Screen* screen = DefaultScreenOfDisplay(DefaultXDisplay());
   Visual* visual = DefaultVisualOfScreen(screen);
   mBackground = gfxXlibSurface::Create(
@@ -1310,7 +1310,7 @@ PluginInstanceParent::BackgroundDescriptor() {

   // XXX refactor me

-#ifdef MOZ_X11
+#if 0
   gfxXlibSurface* xsurf = static_cast<gfxXlibSurface*>(mBackground.get());
   return SurfaceDescriptorX11(xsurf);
 #endif
@@ -1427,7 +1427,7 @@ NPError PluginInstanceParent::NPP_SetWindow(const NPWindow* aWindow) {
   }
 #endif

-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
   const NPSetWindowCallbackStruct* ws_info =
       static_cast<NPSetWindowCallbackStruct*>(aWindow->ws_info);
   window.visualID = ws_info->visual ? ws_info->visual->visualid : 0;
@@ -1621,7 +1621,7 @@ int16_t PluginInstanceParent::NPP_HandleEvent(void* event) {
   }
 #endif

-#if defined(MOZ_X11)
+#if 0
   switch (npevent->type) {
     case GraphicsExpose:
       PLUGIN_LOG_DEBUG(("  schlepping drawable 0x%lx across the pipe\n",
@@ -1641,7 +1641,7 @@ int16_t PluginInstanceParent::NPP_HandleEvent(void* event) {
       // Release any active pointer grab so that the plugin X client can
       // grab the pointer if it wishes.
       Display* dpy = DefaultXDisplay();
-#  ifdef MOZ_WIDGET_GTK
+#  if 0
       // GDK attempts to (asynchronously) track whether there is an active
       // grab so ungrab through GDK.
       //
diff --git a/dom/plugins/ipc/PluginMessageUtils.cpp b/dom/plugins/ipc/PluginMessageUtils.cpp
index e77d3721f5..0ddcc98330 100644
--- a/dom/plugins/ipc/PluginMessageUtils.cpp
+++ b/dom/plugins/ipc/PluginMessageUtils.cpp
@@ -50,7 +50,7 @@ NPRemoteWindow::NPRemoteWindow()
       width(0),
       height(0),
       type(NPWindowTypeDrawable)
-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
       ,
       visualID(0),
       colormap(0)
@@ -82,7 +82,7 @@ ipc::RacyInterruptPolicy MediateRace(const MessageChannel::MessageInfo& parent,
   }
 }

-#if defined(OS_LINUX) || defined(OS_SOLARIS)
+#if defined(OS_SOLARIS)
 static string ReplaceAll(const string& haystack, const string& needle,
                          const string& with) {
   string munged = haystack;
@@ -98,7 +98,7 @@ static string ReplaceAll(const string& haystack, const string& needle,
 #endif

 string MungePluginDsoPath(const string& path) {
-#if defined(OS_LINUX) || defined(OS_SOLARIS)
+#if defined(OS_SOLARIS)
   // https://bugzilla.mozilla.org/show_bug.cgi?id=519601
   return ReplaceAll(path, "netscape", "netsc@pe");
 #else
@@ -107,7 +107,7 @@ string MungePluginDsoPath(const string& path) {
 }

 string UnmungePluginDsoPath(const string& munged) {
-#if defined(OS_LINUX) || defined(OS_SOLARIS)
+#if defined(OS_SOLARIS)
   return ReplaceAll(munged, "netsc@pe", "netscape");
 #else
   return munged;
diff --git a/dom/plugins/ipc/PluginMessageUtils.h b/dom/plugins/ipc/PluginMessageUtils.h
index 87747b115b..0d33a9a5af 100644
--- a/dom/plugins/ipc/PluginMessageUtils.h
+++ b/dom/plugins/ipc/PluginMessageUtils.h
@@ -87,7 +87,7 @@ struct NPRemoteWindow {
   uint32_t height;
   NPRect clipRect;
   NPWindowType type;
-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
   VisualID visualID;
   Colormap colormap;
 #endif /* XP_UNIX */
@@ -113,9 +113,9 @@ struct NPAudioDeviceStateChangedIPC {

 #ifdef XP_WIN
 typedef HWND NativeWindowHandle;
-#elif defined(MOZ_X11)
+#elif 0
 typedef XID NativeWindowHandle;
-#elif defined(XP_DARWIN) || defined(ANDROID)
+#elif defined(XP_DARWIN) || defined(ANDROID) || defined(MOZ_X11)
 typedef intptr_t NativeWindowHandle;  // never actually used, will always be 0
 #else
 #  error Need NativeWindowHandle for this platform
@@ -323,7 +323,7 @@ struct ParamTraits<mozilla::plugins::NPRemoteWindow> {
     WriteParam(aMsg, aParam.height);
     WriteParam(aMsg, aParam.clipRect);
     WriteParam(aMsg, aParam.type);
-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
     aMsg->WriteULong(aParam.visualID);
     aMsg->WriteULong(aParam.colormap);
 #endif
@@ -345,7 +345,7 @@ struct ParamTraits<mozilla::plugins::NPRemoteWindow> {
           ReadParam(aMsg, aIter, &clipRect) && ReadParam(aMsg, aIter, &type)))
       return false;

-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
     unsigned long visualID;
     unsigned long colormap;
     if (!(aMsg->ReadULong(aIter, &visualID) &&
@@ -365,7 +365,7 @@ struct ParamTraits<mozilla::plugins::NPRemoteWindow> {
     aResult->height = height;
     aResult->clipRect = clipRect;
     aResult->type = type;
-#if defined(MOZ_X11) && defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
     aResult->visualID = visualID;
     aResult->colormap = colormap;
 #endif
diff --git a/dom/plugins/ipc/PluginModuleChild.cpp b/dom/plugins/ipc/PluginModuleChild.cpp
index 2e811ceaeb..a66eb54a4e 100644
--- a/dom/plugins/ipc/PluginModuleChild.cpp
+++ b/dom/plugins/ipc/PluginModuleChild.cpp
@@ -12,7 +12,7 @@

 #include "mozilla/ipc/MessageChannel.h"

-#ifdef MOZ_WIDGET_GTK
+#if 0
 #  include <gtk/gtk.h>
 #  include <gdk/gdkx.h>
 #endif
@@ -25,7 +25,7 @@
 #include "nsPluginsDir.h"
 #include "nsXULAppAPI.h"

-#ifdef MOZ_X11
+#if 0
 #  include "nsX11ErrorHandler.h"
 #  include "mozilla/X11Util.h"
 #endif
@@ -100,7 +100,7 @@ PluginModuleChild::PluginModuleChild(bool aIsChrome)
 #if defined(OS_WIN) || defined(OS_MACOSX)
       ,
       mGetEntryPointsFunc(0)
-#elif defined(MOZ_WIDGET_GTK)
+#elif 0
       ,
       mNestedLoopTimerId(0)
 #endif
@@ -254,7 +254,7 @@ bool PluginModuleChild::InitForChrome(const std::string& aPluginFilename,
   // XXX quirks isn't initialized yet
   mAsyncRenderSupport = info.fSupportsAsyncRender;
 #endif
-#if defined(MOZ_X11)
+#if 0
   constexpr auto flash10Head = "Shockwave Flash 10."_ns;
   if (StringBeginsWith(nsDependentCString(info.fDescription), flash10Head)) {
     AddQuirk(QUIRK_FLASH_EXPOSE_COORD_TRANSLATION);
@@ -267,7 +267,7 @@ bool PluginModuleChild::InitForChrome(const std::string& aPluginFilename,
   mozilla::plugins::PluginUtilsOSX::SetProcessName(nameBuffer);
 #endif
   pluginFile.FreePluginInfo(info);
-#if defined(MOZ_X11) || defined(XP_MACOSX)
+#if 0
   if (!mLibrary)
 #endif
   {
@@ -330,7 +330,7 @@ bool PluginModuleChild::InitForChrome(const std::string& aPluginFilename,
   return true;
 }

-#if defined(MOZ_WIDGET_GTK)
+#if 0

 typedef void (*GObjectDisposeFn)(GObject*);
 typedef gboolean (*GtkWidgetScrollEventFn)(GtkWidget*, GdkEventScroll*);
@@ -550,7 +550,7 @@ bool PluginModuleChild::ShouldContinueFromReplyTimeout() {
 }

 bool PluginModuleChild::InitGraphics() {
-#if defined(MOZ_WIDGET_GTK)
+#if 0
   // Work around plugins that don't interact well with GDK
   // client-side windows.
   PR_SetEnv("GDK_NATIVE_WINDOWS=1");
@@ -588,7 +588,7 @@ bool PluginModuleChild::InitGraphics() {
 #else
   // may not be necessary on all platforms
 #endif
-#ifdef MOZ_X11
+#if 0
   // Do this after initializing GDK, or GDK will install its own handler.
   InstallX11ErrorHandler();
 #endif
@@ -596,7 +596,7 @@ bool PluginModuleChild::InitGraphics() {
 }

 void PluginModuleChild::DeinitGraphics() {
-#if defined(MOZ_X11) && defined(NS_FREE_PERMANENT_DATA)
+#if 0
   // We free some data off of XDisplay close hooks, ensure they're
   // run.  Closing the display is pretty scary, so we only do it to
   // silence leak checkers.
@@ -1000,7 +1000,7 @@ NPError _getvalue(NPP aNPP, NPNVariable aVariable, void* aValue) {
   switch (aVariable) {
     // Copied from nsNPAPIPlugin.cpp
     case NPNVToolkit:
-#if defined(MOZ_WIDGET_GTK)
+#if 0
       *static_cast<NPNToolkitType*>(aValue) = NPNVGtk2;
       return NPERR_NO_ERROR;
 #endif
@@ -1026,7 +1026,7 @@ NPError _getvalue(NPP aNPP, NPNVariable aVariable, void* aValue) {
     case NPNVSupportsWindowless:
       *(NPBool*)aValue = true;
       return NPERR_NO_ERROR;
-#if defined(MOZ_WIDGET_GTK)
+#if 0
     case NPNVxDisplay: {
       if (!aNPP) {
         return NPERR_INVALID_INSTANCE_ERROR;
@@ -1556,8 +1556,8 @@ NPError PluginModuleChild::DoNP_Initialize(const PluginSettings& aSettings) {
   SetEventHooks();
 #endif

-#ifdef MOZ_X11
-#  ifdef MOZ_WIDGET_GTK
+#if 0
+#  if 0
   if (!GDK_IS_X11_DISPLAY(gdk_display_get_default())) {
     // We don't support NPAPI plugins on Wayland.
     return NPERR_GENERIC_ERROR;
diff --git a/dom/plugins/ipc/PluginModuleChild.h b/dom/plugins/ipc/PluginModuleChild.h
index 84df35e5d8..4caf4c54bd 100644
--- a/dom/plugins/ipc/PluginModuleChild.h
+++ b/dom/plugins/ipc/PluginModuleChild.h
@@ -206,7 +206,7 @@ class PluginModuleChild : public PPluginModuleChild {
   bool InitGraphics();
   void DeinitGraphics();

-#if defined(MOZ_WIDGET_GTK)
+#if 0
   static gboolean DetectNestedEventLoop(gpointer data);
   static gboolean ProcessBrowserEvents(gpointer data);

@@ -238,7 +238,7 @@ class PluginModuleChild : public PPluginModuleChild {

   PluginSettings mCachedSettings;

-#if defined(MOZ_WIDGET_GTK)
+#if 0
   // If a plugin spins a nested glib event loop in response to a
   // synchronous IPC message from the browser, the loop might break
   // only after the browser responds to a request sent by the
diff --git a/dom/plugins/ipc/PluginModuleParent.cpp b/dom/plugins/ipc/PluginModuleParent.cpp
index c495097caf..085545376f 100644
--- a/dom/plugins/ipc/PluginModuleParent.cpp
+++ b/dom/plugins/ipc/PluginModuleParent.cpp
@@ -50,7 +50,7 @@
 #  include "PluginUtilsWin.h"
 #endif

-#ifdef MOZ_WIDGET_GTK
+#if 0
 #  include <glib.h>
 #elif XP_MACOSX
 #  include "PluginInterposeOSX.h"
@@ -1591,7 +1591,7 @@ mozilla::ipc::IPCResult PluginModuleChromeParent::

 mozilla::ipc::IPCResult PluginModuleParent::RecvBackUpXResources(
     const FileDescriptor& aXSocketFd) {
-#ifndef MOZ_X11
+#if 1
   MOZ_CRASH("This message only makes sense on X11 platforms");
 #else
   MOZ_ASSERT(0 > mPluginXSocketFdDup.get(), "Already backed up X resources??");
@@ -1777,7 +1777,7 @@ void PluginModuleChromeParent::CachedSettingChanged(const char* aPref,
   module->CachedSettingChanged();
 }

-#if defined(XP_UNIX) && !defined(XP_MACOSX)
+#if 0
 nsresult PluginModuleParent::NP_Initialize(NPNetscapeFuncs* bFuncs,
                                            NPPluginFuncs* pFuncs,
                                            NPError* error) {
@@ -1832,6 +1832,22 @@ nsresult PluginModuleChromeParent::NP_Initialize(NPNetscapeFuncs* bFuncs,

   return NS_OK;
 }
+#endif
+
+#if defined(XP_UNIX) && !defined(XP_MACOSX)
+nsresult PluginModuleParent::NP_Initialize(NPNetscapeFuncs* bFuncs,
+                                           NPPluginFuncs* pFuncs,
+                                           NPError* error) {
+*error = NPERR_GENERIC_ERROR;
+return NS_ERROR_FAILURE;
+}
+
+nsresult PluginModuleChromeParent::NP_Initialize(NPNetscapeFuncs* bFuncs,
+                                                 NPPluginFuncs* pFuncs,
+                                                 NPError* error) {
+  *error = NPERR_GENERIC_ERROR;
+  return NS_ERROR_FAILURE;
+}

 #else

@@ -2035,7 +2051,7 @@ class nsCaseInsensitiveUTF8StringArrayComparator {
   }
 };

-#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK)
+#if defined(XP_WIN)
 static void ForceWindowless(nsTArray<nsCString>& names,
                             nsTArray<nsCString>& values) {
   nsCaseInsensitiveUTF8StringArrayComparator comparator;
@@ -2118,7 +2134,7 @@ nsresult PluginModuleParent::NPP_NewInternal(
 #  endif
       ForceWindowless(names, values);
     }
-#elif defined(MOZ_WIDGET_GTK)
+#elif 0
     // We no longer support windowed mode on Linux.
     ForceWindowless(names, values);
 #endif
@@ -2232,7 +2248,7 @@ mozilla::ipc::IPCResult PluginModuleParent::AnswerProcessSomeEvents() {
   return IPC_OK();
 }

-#elif !defined(MOZ_WIDGET_GTK)
+#elif 1
 mozilla::ipc::IPCResult PluginModuleParent::AnswerProcessSomeEvents() {
   MOZ_CRASH("unreached");
 }
diff --git a/dom/plugins/ipc/PluginModuleParent.h b/dom/plugins/ipc/PluginModuleParent.h
index 9fd74904a2..b77279b7f5 100644
--- a/dom/plugins/ipc/PluginModuleParent.h
+++ b/dom/plugins/ipc/PluginModuleParent.h
@@ -288,7 +288,7 @@ class PluginModuleParent : public PPluginModuleParent,
   int32_t mSandboxLevel;
   bool mIsFlashPlugin;

-#ifdef MOZ_X11
+#if 0
   // Dup of plugin's X socket, used to scope its resources to this
   // object instead of the plugin process's lifetime
   ScopedClose mPluginXSocketFdDup;
diff --git a/dom/plugins/ipc/moz.build b/dom/plugins/ipc/moz.build
index 49f1e27670..e97c75d72a 100644
--- a/dom/plugins/ipc/moz.build
+++ b/dom/plugins/ipc/moz.build
@@ -142,9 +142,6 @@ DEFINES['FORCE_PR_LOG'] = True

 if CONFIG['MOZ_WIDGET_TOOLKIT'] != 'gtk':
     CXXFLAGS += CONFIG['TK_CFLAGS']
-else:
-    # Force build against gtk+2 for struct offsets and such.
-    CXXFLAGS += CONFIG['MOZ_GTK2_CFLAGS']

 CXXFLAGS += CONFIG['MOZ_CAIRO_CFLAGS']

diff --git a/dom/plugins/test/moz.build b/dom/plugins/test/moz.build
index 032db35387..dde5c1c31b 100644
--- a/dom/plugins/test/moz.build
+++ b/dom/plugins/test/moz.build
@@ -8,7 +8,7 @@ DIRS += ['testplugin']

 XPCSHELL_TESTS_MANIFESTS += ['unit/xpcshell.ini']

-if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('gtk', 'cocoa', 'windows'):
+if CONFIG['MOZ_WIDGET_TOOLKIT'] in ('cocoa', 'windows'):
     MOCHITEST_MANIFESTS += ['mochitest/mochitest.ini']
     MOCHITEST_CHROME_MANIFESTS += ['mochitest/chrome.ini']
     BROWSER_CHROME_MANIFESTS += ['mochitest/browser.ini']
diff --git a/dom/plugins/test/testplugin/nptest.cpp b/dom/plugins/test/testplugin/nptest.cpp
index 2a9d20cdca..02b39a27cf 100644
--- a/dom/plugins/test/testplugin/nptest.cpp
+++ b/dom/plugins/test/testplugin/nptest.cpp
@@ -2692,7 +2692,7 @@ bool stallPlugin(NPObject* npobj, const NPVariant* args, uint32_t argCount,
   return true;
 }

-#if defined(MOZ_WIDGET_GTK)
+#if 0
 bool getClipboardText(NPObject* npobj, const NPVariant* args, uint32_t argCount,
                       NPVariant* result) {
   NPP npp = static_cast<TestNPObject*>(npobj)->npp;
diff --git a/dom/plugins/test/testplugin/testplugin.mozbuild b/dom/plugins/test/testplugin/testplugin.mozbuild
index 2c466409ea..ad87356e15 100644
--- a/dom/plugins/test/testplugin/testplugin.mozbuild
+++ b/dom/plugins/test/testplugin/testplugin.mozbuild
@@ -18,11 +18,6 @@ if toolkit == 'cocoa':
     UNIFIED_SOURCES += [
         'nptest_macosx.mm'
     ]
-elif toolkit == 'gtk':
-    UNIFIED_SOURCES += [
-        'nptest_gtk2.cpp',
-    ]
-elif toolkit == 'windows':
     UNIFIED_SOURCES += [
         'nptest_windows.cpp',
     ]
@@ -46,14 +41,6 @@ if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'windows':
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa' and CONFIG['TARGET_CPU'] == 'x86_64':
     OS_LIBS += ['-framework Carbon']

-if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'gtk':
-    CXXFLAGS += CONFIG['MOZ_GTK2_CFLAGS']
-    CFLAGS += CONFIG['MOZ_GTK2_CFLAGS']
-    OS_LIBS += CONFIG['MOZ_GTK2_LIBS']
-    OS_LIBS += CONFIG['XLDFLAGS']
-    OS_LIBS += CONFIG['XLIBS']
-    OS_LIBS += CONFIG['XEXT_LIBS']
-
 if CONFIG['MOZ_WIDGET_TOOLKIT'] == 'cocoa':
     FINAL_TARGET = 'dist/plugins/%s.plugin/Contents/MacOS' % cocoa_name
     OBJDIR_FILES.dist.plugins['%s.plugin' % cocoa_name].Contents += ['%s/Info.plist' % relative_path]
diff --git a/gfx/gl/GLContextProviderGLX.cpp b/gfx/gl/GLContextProviderGLX.cpp
index 3df2834ee1..3b6d0e42a0 100644
--- a/gfx/gl/GLContextProviderGLX.cpp
+++ b/gfx/gl/GLContextProviderGLX.cpp
@@ -3,11 +3,11 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

-#ifdef MOZ_WIDGET_GTK
+#if 0
 #  include <gdk/gdk.h>
 #  include <gdk/gdkx.h>
 #  define GET_NATIVE_WINDOW(aWidget) \
-    GDK_WINDOW_XID((GdkWindow*)aWidget->GetNativeData(NS_NATIVE_WINDOW))
+   GDK_WINDOW_XID((GdkWindow*)aWidget->GetNativeData(NS_NATIVE_WINDOW))
 #endif

 #include <X11/Xlib.h>
@@ -42,7 +42,7 @@

 #include "gfxCrashReporterUtils.h"

-#ifdef MOZ_WIDGET_GTK
+#if MOZ_WIDGET_GTK
 #  include "gfxPlatformGtk.h"
 #endif

diff --git a/gfx/gl/GLContextProviderWayland.cpp b/gfx/gl/GLContextProviderWayland.cpp
index 4f7c15380c..25ee2d4354 100644
--- a/gfx/gl/GLContextProviderWayland.cpp
+++ b/gfx/gl/GLContextProviderWayland.cpp
@@ -3,7 +3,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

-#ifdef MOZ_WIDGET_GTK
+#if 0
 #  include <gdk/gdk.h>
 #  include <gdk/gdkx.h>
 #endif
@@ -21,41 +21,24 @@ static class GLContextProviderEGL sGLContextProviderEGL;
 already_AddRefed<GLContext> GLContextProviderWayland::CreateForCompositorWidget(
     CompositorWidget* aCompositorWidget, bool aWebRender,
     bool aForceAccelerated) {
-  if (GDK_IS_X11_DISPLAY(gdk_display_get_default())) {
-    return sGLContextProviderX11.CreateForCompositorWidget(
-        aCompositorWidget, aWebRender, aForceAccelerated);
-  } else {
     return sGLContextProviderEGL.CreateForCompositorWidget(
         aCompositorWidget, aWebRender, aForceAccelerated);
-  }
 }

 /*static*/
 already_AddRefed<GLContext> GLContextProviderWayland::CreateHeadless(
     const GLContextCreateDesc& desc, nsACString* const out_failureId) {
-  if (GDK_IS_X11_DISPLAY(gdk_display_get_default())) {
-    return sGLContextProviderX11.CreateHeadless(desc, out_failureId);
-  } else {
     return sGLContextProviderEGL.CreateHeadless(desc, out_failureId);
-  }
 }

 /*static*/
 GLContext* GLContextProviderWayland::GetGlobalContext() {
-  if (GDK_IS_X11_DISPLAY(gdk_display_get_default())) {
-    return sGLContextProviderX11.GetGlobalContext();
-  } else {
     return sGLContextProviderEGL.GetGlobalContext();
-  }
 }

 /*static*/
 void GLContextProviderWayland::Shutdown() {
-  if (GDK_IS_X11_DISPLAY(gdk_display_get_default())) {
-    sGLContextProviderX11.Shutdown();
-  } else {
     sGLContextProviderEGL.Shutdown();
-  }
 }

 }  // namespace mozilla::gl
diff --git a/gfx/thebes/gfxGdkNativeRenderer.cpp b/gfx/thebes/gfxGdkNativeRenderer.cpp
index 49f3afdb59..95760b16e4 100644
--- a/gfx/thebes/gfxGdkNativeRenderer.cpp
+++ b/gfx/thebes/gfxGdkNativeRenderer.cpp
@@ -7,7 +7,7 @@
 #include "gfxContext.h"
 #include "gfxPlatformGtk.h"

-#ifdef MOZ_X11
+#if 0
 #  include <gdk/gdkx.h>
 #  include "cairo-xlib.h"
 #  include "gfxXlibSurface.h"
diff --git a/gfx/thebes/gfxGdkNativeRenderer.h b/gfx/thebes/gfxGdkNativeRenderer.h
index e11a3ba5d1..1cfaf8c79e 100644
--- a/gfx/thebes/gfxGdkNativeRenderer.h
+++ b/gfx/thebes/gfxGdkNativeRenderer.h
@@ -6,9 +6,9 @@
 #ifndef GFXGDKNATIVERENDER_H_
 #define GFXGDKNATIVERENDER_H_

-#include <gdk/gdk.h>
+//#include <gdk/gdk.h>
 #include "nsSize.h"
-#ifdef MOZ_X11
+#if MOZ_X11
 #  include "gfxXlibNativeRenderer.h"
 #endif

diff --git a/old-configure b/old-configure
index 62d6ff55d9..9125028319 100644
--- a/old-configure
+++ b/old-configure
@@ -746,7 +746,6 @@ GLIB_VERSION=2.42
 GLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_42
 GLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_42
 CAIRO_VERSION=1.10
-GTK2_VERSION=2.18.0
 GTK3_VERSION=3.14.0
 GDK_VERSION_MAX_ALLOWED=GDK_VERSION_3_14
 W32API_VERSION=3.14
@@ -7929,79 +7928,6 @@ cat >> confdefs.h <<EOF
 EOF
 
   fi
-  if test "$MOZ_ENABLE_GTK"; then
-    if test "$MOZ_X11"; then
-      GDK_PACKAGES=gdk-x11-2.0
-    fi
-    cat >> confdefs.pytmp <<EOF
-    (''' GLIB_VERSION_MIN_REQUIRED ''', r''' $GLIB_VERSION_MIN_REQUIRED ''')
-EOF
-cat >> confdefs.h <<EOF
-#define GLIB_VERSION_MIN_REQUIRED $GLIB_VERSION_MIN_REQUIRED
-EOF
-
-    cat >> confdefs.pytmp <<EOF
-    (''' GLIB_VERSION_MAX_ALLOWED ''', r''' $GLIB_VERSION_MAX_ALLOWED ''')
-EOF
-cat >> confdefs.h <<EOF
-#define GLIB_VERSION_MAX_ALLOWED $GLIB_VERSION_MAX_ALLOWED
-EOF
-
-
-    succeeded=no
-
-  if test -z "$PKG_CONFIG"; then
-     echo "*** The pkg-config script could not be found. Make sure it is"
-     echo "*** in your path, or set the PKG_CONFIG environment variable"
-     echo "*** to the full path to pkg-config."
-     echo "*** Or see http://www.freedesktop.org/software/pkgconfig to get pkg-config."
-  else
-     PKG_CONFIG_MIN_VERSION=0.9.0
-     if $PKG_CONFIG --atleast-pkgconfig-version $PKG_CONFIG_MIN_VERSION; then
-        echo $ac_n "checking for gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES""... $ac_c" 1>&6
-echo "configure:7963: checking for gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES" >&5
-
-        if $PKG_CONFIG --exists "gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES" ; then
-            echo "$ac_t""yes" 1>&6
-            succeeded=yes
-
-            echo $ac_n "checking MOZ_GTK2_CFLAGS""... $ac_c" 1>&6
-echo "configure:7970: checking MOZ_GTK2_CFLAGS" >&5
-            MOZ_GTK2_CFLAGS=`$PKG_CONFIG --cflags "gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES"`
-            echo "$ac_t""$MOZ_GTK2_CFLAGS" 1>&6
-
-            echo $ac_n "checking MOZ_GTK2_LIBS""... $ac_c" 1>&6
-echo "configure:7975: checking MOZ_GTK2_LIBS" >&5
-            ## Remove evil flags like -Wl,--export-dynamic
-            MOZ_GTK2_LIBS="`$PKG_CONFIG --libs \"gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES\" |sed s/-Wl,--export-dynamic//g`"
-            echo "$ac_t""$MOZ_GTK2_LIBS" 1>&6
-        else
-            MOZ_GTK2_CFLAGS=""
-            MOZ_GTK2_LIBS=""
-            ## If we have a custom action on failure, don't print errors, but 
-            ## do set a variable so people can do so.
-            MOZ_GTK2_PKG_ERRORS=`$PKG_CONFIG --errors-to-stdout --print-errors "gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES"`
-            echo $MOZ_GTK2_PKG_ERRORS
-        fi
-
-        
-        
-     else
-        echo "*** Your version of pkg-config is too old. You need version $PKG_CONFIG_MIN_VERSION or newer."
-        echo "*** See http://www.freedesktop.org/software/pkgconfig"
-     fi
-  fi
-
-  if test $succeeded = yes; then
-     :
-  else
-     if test "$COMPILE_ENVIRONMENT"; then 
-       { echo "configure: error: Library requirements (gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your libraries are in a nonstandard prefix so pkg-config can find them." 1>&2; echo "configure: error: Library requirements (gtk+-2.0 >= $GTK2_VERSION gtk+-unix-print-2.0 glib-2.0 >= $GLIB_VERSION gobject-2.0 gio-unix-2.0 $GDK_PACKAGES) not met; consider adjusting the PKG_CONFIG_PATH environment variable if your libraries are in a nonstandard prefix so pkg-config can find them." 1>&5; exit 1; }
-     fi
-  fi
-
-    MOZ_GTK2_CFLAGS="-I${_topsrcdir}/widget/gtk/compat $MOZ_GTK2_CFLAGS"
-  fi
 fi # COMPILE_ENVIRONMENT
 
 
@@ -10619,8 +10545,6 @@ sed 's/$/,/' >> $CONFIG_STATUS <<EOF
     (''' MOZ_ANDROID_MAX_SDK_VERSION ''', r''' $MOZ_ANDROID_MAX_SDK_VERSION ''')
     (''' MOZ_GTK3_CFLAGS ''', list(split(r''' $MOZ_GTK3_CFLAGS ''')))
     (''' MOZ_GTK3_LIBS ''', list(split(r''' $MOZ_GTK3_LIBS ''')))
-    (''' MOZ_GTK2_CFLAGS ''', list(split(r''' $MOZ_GTK2_CFLAGS ''')))
-    (''' MOZ_GTK2_LIBS ''', list(split(r''' $MOZ_GTK2_LIBS ''')))
     (''' MOZ_FS_LAYOUT ''', r''' $MOZ_FS_LAYOUT ''')
     (''' TK_CFLAGS ''', list(split(r''' $TK_CFLAGS ''')))
     (''' TK_LIBS ''', list(split(r''' $TK_LIBS ''')))
diff --git a/widget/gtk/mozgtk/gtk2/moz.build b/widget/gtk/mozgtk/gtk2/moz.build
deleted file mode 100644
index d07fd06dfd..0000000000
--- a/widget/gtk/mozgtk/gtk2/moz.build
+++ /dev/null
@@ -1,40 +0,0 @@
-# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
-# vim: set filetype=python:
-# This Source Code Form is subject to the terms of the Mozilla Public
-# License, v. 2.0. If a copy of the MPL was not distributed with this
-# file, You can obtain one at http://mozilla.org/MPL/2.0/.
-
-SOURCES += [
-    '../mozgtk.c',
-]
-
-DEFINES['GTK3_SYMBOLS'] = True
-
-SharedLibrary('mozgtk2')
-
-SHARED_LIBRARY_NAME = 'mozgtk'
-
-FINAL_TARGET = 'dist/bin/gtk2'
-
-# If LDFLAGS contains -Wl,--as-needed or if it's the default for the toolchain,
-# we need to add -Wl,--no-as-needed before the gtk libraries, otherwise the
-# linker will drop those dependencies because no symbols are used from them.
-# But those dependencies need to be kept for things to work properly.
-# Ideally, we'd only add -Wl,--no-as-needed if necessary, but it's just simpler
-# to add it unconditionally. This library is also simple enough that forcing
-# -Wl,--as-needed after the gtk libraries is not going to make a significant
-# difference.
-if CONFIG['GCC_USE_GNU_LD']:
-    no_as_needed = ['-Wl,--no-as-needed']
-    as_needed = ['-Wl,--as-needed']
-else:
-    no_as_needed = []
-    as_needed = []
-
-OS_LIBS += [f for f in CONFIG['MOZ_GTK2_LIBS'] if f.startswith('-L')]
-OS_LIBS += no_as_needed
-OS_LIBS += [
-    'gtk-x11-2.0',
-    'gdk-x11-2.0',
-]
-OS_LIBS += as_needed
diff --git a/widget/gtk/mozgtk/gtk3/moz.build b/widget/gtk/mozgtk/gtk3/moz.build
index 4e9379565d..20b961371e 100644
--- a/widget/gtk/mozgtk/gtk3/moz.build
+++ b/widget/gtk/mozgtk/gtk3/moz.build
@@ -8,7 +8,6 @@ SOURCES += [
     '../mozgtk.c',
 ]

-DEFINES['GTK2_SYMBOLS'] = True

 SharedLibrary('mozgtk')

diff --git a/widget/gtk/mozgtk/moz.build b/widget/gtk/mozgtk/moz.build
index 528e2e9d0f..d32ee829e7 100644
--- a/widget/gtk/mozgtk/moz.build
+++ b/widget/gtk/mozgtk/moz.build
@@ -4,4 +4,4 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.

-DIRS += ['stub', 'gtk2', 'gtk3']
+DIRS += ['stub', 'gtk3']
diff --git a/widget/gtk/mozgtk/mozgtk.c b/widget/gtk/mozgtk/mozgtk.c
index 8cc4da33f6..4ba73523fc 100644
--- a/widget/gtk/mozgtk/mozgtk.c
+++ b/widget/gtk/mozgtk/mozgtk.c
@@ -647,21 +647,6 @@ STUB(gtk_color_chooser_get_rgba)
 STUB(gtk_color_chooser_set_use_alpha)
 #endif

-#ifdef GTK2_SYMBOLS
-STUB(gdk_drawable_get_screen)
-STUB(gdk_rgb_get_colormap)
-STUB(gdk_rgb_get_visual)
-STUB(gdk_window_lookup)
-STUB(gdk_window_set_back_pixmap)
-STUB(gdk_x11_colormap_foreign_new)
-STUB(gdk_x11_colormap_get_xcolormap)
-STUB(gdk_x11_drawable_get_xdisplay)
-STUB(gdk_x11_drawable_get_xid)
-STUB(gdk_x11_window_get_drawable_impl)
-STUB(gdkx_visual_get)
-STUB(gtk_object_get_type)
-#endif
-
 #ifndef GTK3_SYMBOLS
 // Only define the following workaround when using GTK3, which we detect
 // by checking if GTK3 stubs are not provided.
diff --git a/widget/gtk/mozgtk/stub/moz.build b/widget/gtk/mozgtk/stub/moz.build
index 1a8e210018..3ed3d1be48 100644
--- a/widget/gtk/mozgtk/stub/moz.build
+++ b/widget/gtk/mozgtk/stub/moz.build
@@ -8,7 +8,7 @@ SOURCES += [
     '../mozgtk.c',
 ]

-for var in ('COMMON_SYMBOLS', 'GTK2_SYMBOLS', 'GTK3_SYMBOLS'):
+for var in ('COMMON_SYMBOLS', 'GTK3_SYMBOLS'):
     DEFINES[var] = True

 SharedLibrary('mozgtk_stub')
diff --git a/widget/gtk/nsWindow.h b/widget/gtk/nsWindow.h
index 29f40cb636..12aed01bb0 100644
--- a/widget/gtk/nsWindow.h
+++ b/widget/gtk/nsWindow.h
@@ -8,14 +8,14 @@
 #ifndef __nsWindow_h__
 #define __nsWindow_h__

-#include <gdk/gdk.h>
+//#include <gdk/gdk.h>
 #include <gtk/gtk.h>
 #ifdef MOZ_X11
 #  include <gdk/gdkx.h>
 #  include "X11UndefineNone.h"
 #endif /* MOZ_X11 */
 #ifdef MOZ_WAYLAND
-#  include <gdk/gdkwayland.h>
+//#  include <gdk/gdkwayland.h>
 #  include "base/thread.h"
 #  include "WaylandVsyncSource.h"
 #endif