Bug 1278282 - Remove the 'MOZ_WIDGET_GTK == 2' defines r=karlt,lsalzman
authorSylvestre Ledru <sledru@mozilla.com>
Wed, 10 Jan 2018 08:52:04 +0100
changeset 398762 26fa4e61b9bc
parent 398761 28340f2e2631
child 398763 4edc392d61fa
push id33232
push usernerli@mozilla.com
push date2018-01-11 21:53 +0000
treeherdermozilla-central@185d2695bf96 [default view] [failures only]
perfherder[talos] [build metrics] [platform microbench] (compared to previous push)
reviewerskarlt, lsalzman
bugs1278282
milestone59.0a1
Bug 1278282 - Remove the 'MOZ_WIDGET_GTK == 2' defines r=karlt,lsalzman MozReview-Commit-ID: 3v8D600g8St
accessible/atk/Platform.cpp
dom/plugins/base/nsNPAPIPlugin.cpp
dom/plugins/base/nsPluginsDirUnix.cpp
gfx/thebes/gfxGdkNativeRenderer.cpp
gfx/thebes/gfxGdkNativeRenderer.h
gfx/thebes/gfxPlatformGtk.cpp
gfx/thebes/gfxPlatformGtk.h
image/decoders/icon/nsIconModule.cpp
layout/xul/nsMenuPopupFrame.cpp
modules/libpref/init/all.js
testing/tools/screenshot/gdk-screenshot.cpp
toolkit/components/remote/nsGTKRemoteService.cpp
toolkit/crashreporter/client/crashreporter_linux.cpp
toolkit/xre/glxtest.cpp
toolkit/xre/nsAppRunner.cpp
toolkit/xre/nsEmbedFunctions.cpp
toolkit/xre/nsNativeAppSupportUnix.cpp
toolkit/xre/nsX11ErrorHandler.cpp
widget/gtk/IMContextWrapper.cpp
widget/gtk/NativeKeyBindings.cpp
widget/gtk/gtkdrawing.h
widget/gtk/mozcontainer.cpp
widget/gtk/nsDragService.cpp
widget/gtk/nsNativeThemeGTK.cpp
widget/gtk/nsPrintDialogGTK.cpp
widget/gtk/nsWindow.cpp
widget/gtk/nsWindow.h
xpcom/base/nsSystemInfo.cpp
xpcom/build/nsXULAppAPI.h
xpcom/glue/standalone/nsXPCOMGlue.cpp
--- a/accessible/atk/Platform.cpp
+++ b/accessible/atk/Platform.cpp
@@ -64,24 +64,16 @@ static GnomeAccessibilityModule sAtkBrid
     "libatk-bridge.a(libatk-bridge.so.0)", nullptr,
 #else
     "libatk-bridge.so", nullptr,
 #endif
     "gnome_accessibility_module_init", nullptr,
     "gnome_accessibility_module_shutdown", nullptr
 };
 
-#if (MOZ_WIDGET_GTK == 2)
-static GnomeAccessibilityModule sGail = {
-    "libgail.so", nullptr,
-    "gnome_accessibility_module_init", nullptr,
-    "gnome_accessibility_module_shutdown", nullptr
-};
-#endif
-
 static nsresult
 LoadGtkModule(GnomeAccessibilityModule& aModule)
 {
     NS_ENSURE_ARG(aModule.libName);
 
     if (!(aModule.lib = PR_LoadLibrary(aModule.libName))) {
         //try to load the module with "gtk-2.0/modules" appended
         char *curLibPath = PR_GetLibraryPath();
@@ -97,21 +89,17 @@ LoadGtkModule(GnomeAccessibilityModule& 
         int16_t subLen = 0;
         while (loc2 >= 0) {
             loc2 = libPath.FindChar(':', loc1);
             if (loc2 < 0)
                 subLen = libPath.Length() - loc1;
             else
                 subLen = loc2 - loc1;
             nsAutoCString sub(Substring(libPath, loc1, subLen));
-#if (MOZ_WIDGET_GTK == 2)
-            sub.AppendLiteral("/gtk-2.0/modules/");
-#else
             sub.AppendLiteral("/gtk-3.0/modules/");
-#endif
             sub.Append(aModule.libName);
             aModule.lib = PR_LoadLibrary(sub.get());
             if (aModule.lib)
                 break;
 
             loc1 = loc2+1;
         }
         if (!aModule.lib)
@@ -171,23 +159,16 @@ a11y::PlatformInit()
       if (atkMajorVersion != 0L) {
         atkMinorVersion = strtol(endPtr + 1, &endPtr, 10);
         if (atkMinorVersion != 0L)
           atkMicroVersion = strtol(endPtr + 1, &endPtr, 10);
       }
     }
   }
 
-#if (MOZ_WIDGET_GTK == 2)
-  // Load and initialize gail library.
-  nsresult rv = LoadGtkModule(sGail);
-  if (NS_SUCCEEDED(rv))
-    (*sGail.init)();
-#endif
-
   // Initialize the MAI Utility class, it will overwrite gail_util.
   g_type_class_unref(g_type_class_ref(mai_util_get_type()));
 
   // Init atk-bridge now
   PR_SetEnv("NO_AT_BRIDGE=0");
 #ifdef MOZ_WIDGET_GTK
   if (atk_bridge_adaptor_init) {
     atk_bridge_adaptor_init(nullptr, nullptr);
@@ -231,29 +212,16 @@ a11y::PlatformShutdown()
         // an exit function registered will take care of it
         // if (sAtkBridge.shutdown)
         //     (*sAtkBridge.shutdown)();
         // PR_UnloadLibrary(sAtkBridge.lib);
         sAtkBridge.lib = nullptr;
         sAtkBridge.init = nullptr;
         sAtkBridge.shutdown = nullptr;
     }
-#if (MOZ_WIDGET_GTK == 2)
-    if (sGail.lib) {
-        // Do not shutdown gail because
-        // 1) Maybe it's not init-ed by us. e.g. GtkEmbed
-        // 2) We need it to avoid assert in spi_atk_tidy_windows
-        // if (sGail.shutdown)
-        //   (*sGail.shutdown)();
-        // PR_UnloadLibrary(sGail.lib);
-        sGail.lib = nullptr;
-        sGail.init = nullptr;
-        sGail.shutdown = nullptr;
-    }
-#endif
     // if (sATKLib) {
     //     PR_UnloadLibrary(sATKLib);
     //     sATKLib = nullptr;
     // }
 }
 
   static const char sAccEnv [] = "GNOME_ACCESSIBILITY";
 #ifdef MOZ_ENABLE_DBUS
--- a/dom/plugins/base/nsNPAPIPlugin.cpp
+++ b/dom/plugins/base/nsNPAPIPlugin.cpp
@@ -52,19 +52,16 @@
 #include "nsCocoaFeatures.h"
 #include "PluginUtilsOSX.h"
 #endif
 
 // needed for nppdf plugin
 #if (MOZ_WIDGET_GTK)
 #include <gdk/gdk.h>
 #include <gdk/gdkx.h>
-#if (MOZ_WIDGET_GTK == 2)
-#include "gtk2xtbin.h"
-#endif
 #endif
 
 #include "nsJSUtils.h"
 #include "nsJSNPRuntime.h"
 #include "nsIHttpAuthManager.h"
 #include "nsICookieService.h"
 #include "nsILoadContext.h"
 #include "nsIDocShell.h"
@@ -1336,29 +1333,16 @@ NPError
           needsXEmbed = 0;
         }
       }
       if (windowless || needsXEmbed) {
         (*(Display **)result) = mozilla::DefaultXDisplay();
         return NPERR_NO_ERROR;
       }
     }
-#if (MOZ_WIDGET_GTK == 2)
-    // adobe nppdf calls XtGetApplicationNameAndClass(display,
-    // &instance, &class) we have to init Xt toolkit before get
-    // XtDisplay just call gtk_xtbin_new(w,0) once
-    static GtkWidget *gtkXtBinHolder = 0;
-    if (!gtkXtBinHolder) {
-      gtkXtBinHolder = gtk_xtbin_new(gdk_get_default_root_window(),0);
-      // it crashes on destroy, let it leak
-      // gtk_widget_destroy(gtkXtBinHolder);
-    }
-    (*(Display **)result) =  GTK_XTBIN(gtkXtBinHolder)->xtdisplay;
-    return NPERR_NO_ERROR;
-#endif
 #endif
     return NPERR_GENERIC_ERROR;
   }
 
   case NPNVxtAppContext:
     return NPERR_GENERIC_ERROR;
 #endif
 
--- a/dom/plugins/base/nsPluginsDirUnix.cpp
+++ b/dom/plugins/base/nsPluginsDirUnix.cpp
@@ -34,182 +34,16 @@
 #define DEFAULT_X11_PATH "/usr/X11R6/lib"
 #undef LOCAL_PLUGIN_DLL_SUFFIX
 #define LOCAL_PLUGIN_DLL_SUFFIX ".dylib"
 #define LOCAL_PLUGIN_DLL_ALT_SUFFIX ".so"
 #else
 #define DEFAULT_X11_PATH ""
 #endif
 
-#if (MOZ_WIDGET_GTK == 2)
-
-#define PLUGIN_MAX_LEN_OF_TMP_ARR 512
-
-static void DisplayPR_LoadLibraryErrorMessage(const char *libName)
-{
-    char errorMsg[PLUGIN_MAX_LEN_OF_TMP_ARR] = "Cannot get error from NSPR.";
-    if (PR_GetErrorTextLength() < (int) sizeof(errorMsg))
-        PR_GetErrorText(errorMsg);
-
-    fprintf(stderr, "LoadPlugin: failed to initialize shared library %s [%s]\n",
-        libName, errorMsg);
-}
-
-static void SearchForSoname(const char* name, char** soname)
-{
-    if (!(name && soname))
-        return;
-    PRDir *fdDir = PR_OpenDir(DEFAULT_X11_PATH);
-    if (!fdDir)
-        return;
-
-    int n = strlen(name);
-    PRDirEntry *dirEntry;
-    while ((dirEntry = PR_ReadDir(fdDir, PR_SKIP_BOTH))) {
-        if (!PL_strncmp(dirEntry->name, name, n)) {
-            if (dirEntry->name[n] == '.' && dirEntry->name[n+1] && !dirEntry->name[n+2]) {
-                // name.N, wild guess this is what we need
-                char out[PLUGIN_MAX_LEN_OF_TMP_ARR] = DEFAULT_X11_PATH;
-                PL_strcat(out, dirEntry->name);
-                *soname = PL_strdup(out);
-               break;
-            }
-        }
-    }
-
-    PR_CloseDir(fdDir);
-}
-
-static bool LoadExtraSharedLib(const char *name, char **soname, bool tryToGetSoname)
-{
-    bool ret = true;
-    PRLibSpec tempSpec;
-    PRLibrary *handle;
-    tempSpec.type = PR_LibSpec_Pathname;
-    tempSpec.value.pathname = name;
-    handle = PR_LoadLibraryWithFlags(tempSpec, PR_LD_NOW|PR_LD_GLOBAL);
-    if (!handle) {
-        ret = false;
-        DisplayPR_LoadLibraryErrorMessage(name);
-        if (tryToGetSoname) {
-            SearchForSoname(name, soname);
-            if (*soname) {
-                ret = LoadExtraSharedLib((const char *) *soname, nullptr, false);
-            }
-        }
-    }
-    return ret;
-}
-
-#define PLUGIN_MAX_NUMBER_OF_EXTRA_LIBS 32
-#define PREF_PLUGINS_SONAME "plugin.soname.list"
-#if defined(SOLARIS) || defined(HPUX)
-#define DEFAULT_EXTRA_LIBS_LIST "libXt" LOCAL_PLUGIN_DLL_SUFFIX ":libXext" LOCAL_PLUGIN_DLL_SUFFIX ":libXm" LOCAL_PLUGIN_DLL_SUFFIX
-#else
-#define DEFAULT_EXTRA_LIBS_LIST "libXt" LOCAL_PLUGIN_DLL_SUFFIX ":libXext" LOCAL_PLUGIN_DLL_SUFFIX
-#endif
-/*
- this function looks for
- user_pref("plugin.soname.list", "/usr/X11R6/lib/libXt.so.6:libXext.so");
- in user's pref.js
- and loads all libs in specified order
-*/
-
-static void LoadExtraSharedLibs()
-{
-    // check out if user's prefs.js has libs name
-    nsresult res;
-    nsCOMPtr<nsIPrefBranch> prefs(do_GetService(NS_PREFSERVICE_CONTRACTID, &res));
-    if (NS_SUCCEEDED(res) && (prefs != nullptr)) {
-        char *sonameList = nullptr;
-        bool prefSonameListIsSet = true;
-        res = prefs->GetCharPref(PREF_PLUGINS_SONAME, &sonameList);
-        if (!sonameList) {
-            // pref is not set, lets use hardcoded list
-            prefSonameListIsSet = false;
-            sonameList = PL_strdup(DEFAULT_EXTRA_LIBS_LIST);
-        }
-        if (sonameList) {
-            char *arrayOfLibs[PLUGIN_MAX_NUMBER_OF_EXTRA_LIBS] = {0};
-            int numOfLibs = 0;
-            char *nextToken;
-            char *p = nsCRT::strtok(sonameList,":",&nextToken);
-            if (p) {
-                while (p && numOfLibs < PLUGIN_MAX_NUMBER_OF_EXTRA_LIBS) {
-                    arrayOfLibs[numOfLibs++] = p;
-                    p = nsCRT::strtok(nextToken,":",&nextToken);
-                }
-            } else // there is just one lib
-                arrayOfLibs[numOfLibs++] = sonameList;
-
-            char sonameListToSave[PLUGIN_MAX_LEN_OF_TMP_ARR] = "";
-            for (int i=0; i<numOfLibs; i++) {
-                // trim out head/tail white spaces (just in case)
-                bool head = true;
-                p = arrayOfLibs[i];
-                while (*p) {
-                    if (*p == ' ' || *p == '\t') {
-                        if (head) {
-                            arrayOfLibs[i] = ++p;
-                        } else {
-                            *p = 0;
-                        }
-                    } else {
-                        head = false;
-                        p++;
-                    }
-                }
-                if (!arrayOfLibs[i][0]) {
-                    continue; // null string
-                }
-                bool tryToGetSoname = true;
-                if (PL_strchr(arrayOfLibs[i], '/')) {
-                    //assuming it's real name, try to stat it
-                    struct stat st;
-                    if (stat((const char*) arrayOfLibs[i], &st)) {
-                        //get just a file name
-                        arrayOfLibs[i] = PL_strrchr(arrayOfLibs[i], '/') + 1;
-                    } else
-                        tryToGetSoname = false;
-                }
-                char *soname = nullptr;
-                if (LoadExtraSharedLib(arrayOfLibs[i], &soname, tryToGetSoname)) {
-                    //construct soname's list to save in prefs
-                    p = soname ? soname : arrayOfLibs[i];
-                    int n = PLUGIN_MAX_LEN_OF_TMP_ARR -
-                        (strlen(sonameListToSave) + strlen(p));
-                    if (n > 0) {
-                        PL_strcat(sonameListToSave, p);
-                        PL_strcat(sonameListToSave,":");
-                    }
-                    if (soname) {
-                        PL_strfree(soname); // it's from strdup
-                    }
-                    if (numOfLibs > 1)
-                        arrayOfLibs[i][strlen(arrayOfLibs[i])] = ':'; //restore ":" in sonameList
-                }
-            }
-
-            // Check whether sonameListToSave is a empty String, Bug: 329205
-            if (sonameListToSave[0])
-                for (p = &sonameListToSave[strlen(sonameListToSave) - 1]; *p == ':'; p--)
-                    *p = 0; //delete tail ":" delimiters
-
-            if (!prefSonameListIsSet || PL_strcmp(sonameList, sonameListToSave)) {
-                // if user specified some bogus soname I overwrite it here,
-                // otherwise it'll decrease performance by calling popen() in SearchForSoname
-                // every time for each bogus name
-                prefs->SetCharPref(PREF_PLUGINS_SONAME, (const char *)sonameListToSave);
-            }
-            PL_strfree(sonameList);
-        }
-    }
-}
-#endif //MOZ_WIDGET_GTK == 2
-
 /* nsPluginsDir implementation */
 
 bool nsPluginsDir::IsPluginFile(nsIFile* file)
 {
     nsAutoCString filename;
     if (NS_FAILED(file->GetNativeLeafName(filename)))
         return false;
 
@@ -250,53 +84,18 @@ nsresult nsPluginFile::LoadPlugin(PRLibr
     nsresult rv;
     nsAutoCString path;
     rv = mPlugin->GetNativePath(path);
     if (NS_FAILED(rv))
         return rv;
 
     libSpec.value.pathname = path.get();
 
-#if (MOZ_WIDGET_GTK == 2)
-
-    // Normally, Mozilla isn't linked against libXt and libXext
-    // since it's a Gtk/Gdk application.  On the other hand,
-    // legacy plug-ins expect the libXt and libXext symbols
-    // to already exist in the global name space.  This plug-in
-    // wrapper is linked against libXt and libXext, but since
-    // we never call on any of these libraries, plug-ins still
-    // fail to resolve Xt symbols when trying to do a dlopen
-    // at runtime.  Explicitly opening Xt/Xext into the global
-    // namespace before attempting to load the plug-in seems to
-    // work fine.
-
-
-#if defined(SOLARIS) || defined(HPUX)
-    // Acrobat/libXm: Lazy resolving might cause crash later (bug 211587)
-    *outLibrary = PR_LoadLibraryWithFlags(libSpec, PR_LD_NOW);
-    pLibrary = *outLibrary;
-#else
-    // Some dlopen() doesn't recover from a failed PR_LD_NOW (bug 223744)
     *outLibrary = PR_LoadLibraryWithFlags(libSpec, 0);
     pLibrary = *outLibrary;
-#endif
-    if (!pLibrary) {
-        LoadExtraSharedLibs();
-        // try reload plugin once more
-        *outLibrary = PR_LoadLibraryWithFlags(libSpec, 0);
-        pLibrary = *outLibrary;
-        if (!pLibrary) {
-            DisplayPR_LoadLibraryErrorMessage(libSpec.value.pathname);
-            return NS_ERROR_FAILURE;
-        }
-    }
-#else
-    *outLibrary = PR_LoadLibraryWithFlags(libSpec, 0);
-    pLibrary = *outLibrary;
-#endif  // MOZ_WIDGET_GTK == 2
 
 #ifdef DEBUG
     printf("LoadPlugin() %s returned %lx\n",
            libSpec.value.pathname, (unsigned long)pLibrary);
 #endif
 
     if (!pLibrary) {
         return NS_ERROR_FAILURE;
--- a/gfx/thebes/gfxGdkNativeRenderer.cpp
+++ b/gfx/thebes/gfxGdkNativeRenderer.cpp
@@ -7,63 +7,10 @@
 #include "gfxContext.h"
 #include "gfxPlatformGtk.h"
 
 #ifdef MOZ_X11
 #include <gdk/gdkx.h>
 #include "cairo-xlib.h"
 #include "gfxXlibSurface.h"
 
-#if (MOZ_WIDGET_GTK == 2)
-nsresult
-gfxGdkNativeRenderer::DrawWithXlib(cairo_surface_t* surface,
-                                   nsIntPoint offset,
-                                   mozilla::gfx::IntRect* clipRects, uint32_t numClipRects)
-{
-    GdkDrawable *drawable = gfxPlatformGtk::GetGdkDrawable(surface);
-    if (!drawable) {
-        int depth = cairo_xlib_surface_get_depth(surface);
-        GdkScreen* screen = gdk_colormap_get_screen(mColormap);
-        drawable =
-            gdk_pixmap_foreign_new_for_screen(screen, cairo_xlib_surface_get_drawable(surface),
-                                              cairo_xlib_surface_get_width(surface),
-                                              cairo_xlib_surface_get_height(surface),
-                                              depth);
-        if (!drawable)
-            return NS_ERROR_FAILURE;
-
-        gdk_drawable_set_colormap(drawable, mColormap);
-        gfxPlatformGtk::SetGdkDrawable(surface, drawable);
-        g_object_unref(drawable); // The drawable now belongs to |surface|.
-    }
-    
-    GdkRectangle clipRect;
-    if (numClipRects) {
-        NS_ASSERTION(numClipRects == 1, "Too many clip rects");
-        clipRect.x = clipRects[0].x;
-        clipRect.y = clipRects[0].y;
-        clipRect.width = clipRects[0].width;
-        clipRect.height = clipRects[0].height;
-    }
-
-    return DrawWithGDK(drawable, offset.x, offset.y,
-                       numClipRects ? &clipRect : nullptr, numClipRects);
-}
-
-void
-gfxGdkNativeRenderer::Draw(gfxContext* ctx, mozilla::gfx::IntSize size,
-                           uint32_t flags, GdkColormap* colormap)
-{
-    mColormap = colormap;
-
-    Visual* visual =
-        gdk_x11_visual_get_xvisual(gdk_colormap_get_visual(colormap));
-    Screen* screen =
-        gdk_x11_screen_get_xscreen(gdk_colormap_get_screen(colormap));
-
-    gfxXlibNativeRenderer::Draw(ctx, size, flags, screen, visual);
-}
-
-#else
-// TODO GTK3
-#endif
 
 #endif
--- a/gfx/thebes/gfxGdkNativeRenderer.h
+++ b/gfx/thebes/gfxGdkNativeRenderer.h
@@ -30,21 +30,16 @@ public:
      * Perform the native drawing.
      * @param offsetX draw at this offset into the given drawable
      * @param offsetY draw at this offset into the given drawable
      * @param clipRects an array of rects; clip to the union
      * @param numClipRects the number of rects in the array, or zero if
      * no clipping is required
      */
 
-#if (MOZ_WIDGET_GTK == 2)
-    virtual nsresult DrawWithGDK(GdkDrawable * drawable, gint offsetX, 
-            gint offsetY, GdkRectangle * clipRects, uint32_t numClipRects) = 0;
-#endif
-
     enum {
         // If set, then Draw() is opaque, i.e., every pixel in the intersection
         // of the clipRect and (offset.x,offset.y,bounds.width,bounds.height)
         // will be set and there is no dependence on what the existing pixels
         // in the drawable are set to.
         DRAW_IS_OPAQUE =
 #ifdef MOZ_X11
             gfxXlibNativeRenderer::DRAW_IS_OPAQUE
@@ -62,27 +57,20 @@ public:
     };
 
     /**
      * @param flags see above
      * @param bounds Draw()'s drawing is guaranteed to be restricted to
      * the rectangle (offset.x,offset.y,bounds.width,bounds.height)
      * @param dpy a display to use for the drawing if ctx doesn't have one
      */
-#if (MOZ_WIDGET_GTK == 2)
-    void Draw(gfxContext* ctx, mozilla::gfx::IntSize size,
-              uint32_t flags, GdkColormap* colormap);
-#endif
 
 private:
 #ifdef MOZ_X11
     // for gfxXlibNativeRenderer:
     virtual nsresult DrawWithXlib(cairo_surface_t* surface,
                                   nsIntPoint offset,
                                   mozilla::gfx::IntRect* clipRects, uint32_t numClipRects) override;
 
-#if (MOZ_WIDGET_GTK == 2)
-    GdkColormap *mColormap;
-#endif
 #endif
 };
 
 #endif /*GFXGDKNATIVERENDER_H_*/
--- a/gfx/thebes/gfxPlatformGtk.cpp
+++ b/gfx/thebes/gfxPlatformGtk.cpp
@@ -62,20 +62,16 @@
 
 #define GFX_PREF_MAX_GENERIC_SUBSTITUTIONS "gfx.font_rendering.fontconfig.max_generic_substitutions"
 
 using namespace mozilla;
 using namespace mozilla::gfx;
 using namespace mozilla::unicode;
 using mozilla::dom::SystemFontListEntry;
 
-#if (MOZ_WIDGET_GTK == 2)
-static cairo_user_data_key_t cairo_gdk_drawable_key;
-#endif
-
 gfxPlatformGtk::gfxPlatformGtk()
 {
     if (!gfxPlatform::IsHeadless()) {
         gtk_init(nullptr, nullptr);
     }
 
     mMaxGenericSubstitutions = UNINITIALIZED_VALUE;
 
@@ -527,61 +523,16 @@ gfxPlatformGtk::GetPlatformCMSOutputProf
             }
 #endif
         }
     }
 #endif
 }
 
 
-#if (MOZ_WIDGET_GTK == 2)
-void
-gfxPlatformGtk::SetGdkDrawable(cairo_surface_t *target,
-                               GdkDrawable *drawable)
-{
-    if (cairo_surface_status(target))
-        return;
-
-    g_object_ref(drawable);
-
-    cairo_surface_set_user_data (target,
-                                 &cairo_gdk_drawable_key,
-                                 drawable,
-                                 g_object_unref);
-}
-
-GdkDrawable *
-gfxPlatformGtk::GetGdkDrawable(cairo_surface_t *target)
-{
-    if (cairo_surface_status(target))
-        return nullptr;
-
-    GdkDrawable *result;
-
-    result = (GdkDrawable*) cairo_surface_get_user_data (target,
-                                                         &cairo_gdk_drawable_key);
-    if (result)
-        return result;
-
-#ifdef MOZ_X11
-    if (cairo_surface_get_type(target) != CAIRO_SURFACE_TYPE_XLIB)
-        return nullptr;
-
-    // try looking it up in gdk's table
-    result = (GdkDrawable*) gdk_xid_table_lookup(cairo_xlib_surface_get_drawable(target));
-    if (result) {
-        SetGdkDrawable(target, result);
-        return result;
-    }
-#endif
-
-    return nullptr;
-}
-#endif
-
 #ifdef GL_PROVIDER_GLX
 
 class GLXVsyncSource final : public VsyncSource
 {
 public:
   GLXVsyncSource()
   {
     MOZ_ASSERT(NS_IsMainThread());
--- a/gfx/thebes/gfxPlatformGtk.h
+++ b/gfx/thebes/gfxPlatformGtk.h
@@ -6,22 +6,16 @@
 #ifndef GFX_PLATFORM_GTK_H
 #define GFX_PLATFORM_GTK_H
 
 #include "gfxPlatform.h"
 #include "nsAutoRef.h"
 #include "nsTArray.h"
 #include "mozilla/gfx/gfxVars.h"
 
-#if (MOZ_WIDGET_GTK == 2)
-extern "C" {
-    typedef struct _GdkDrawable GdkDrawable;
-}
-#endif
-
 #ifdef MOZ_X11
 struct _XDisplay;
 typedef struct _XDisplay Display;
 #endif // MOZ_X11
 
 namespace mozilla {
     namespace dom {
         class SystemFontListEntry;
@@ -89,22 +83,16 @@ public:
 
     /**
      * Calls XFlush if xrender is enabled.
      */
     virtual void FlushContentDrawing() override;
 
     FT_Library GetFTLibrary() override;
 
-#if (MOZ_WIDGET_GTK == 2)
-    static void SetGdkDrawable(cairo_surface_t *target,
-                               GdkDrawable *drawable);
-    static GdkDrawable *GetGdkDrawable(cairo_surface_t *target);
-#endif
-
     static int32_t GetFontScaleDPI();
     static double  GetFontScaleFactor();
 
 #ifdef MOZ_X11
     virtual void GetAzureBackendInfo(mozilla::widget::InfoObject &aObj) override {
       gfxPlatform::GetAzureBackendInfo(aObj);
       aObj.DefineProperty("CairoUseXRender", mozilla::gfx::gfxVars::UseXRender());
     }
--- a/image/decoders/icon/nsIconModule.cpp
+++ b/image/decoders/icon/nsIconModule.cpp
@@ -41,19 +41,16 @@ static const mozilla::Module::ContractID
 
 static const mozilla::Module::CategoryEntry kIconCategories[] = {
   { nullptr }
 };
 
 static void
 IconDecoderModuleDtor()
 {
-#if (MOZ_WIDGET_GTK == 2)
-  nsIconChannel::Shutdown();
-#endif
 }
 
 static const mozilla::Module kIconModule = {
   mozilla::Module::kVersion,
   kIconCIDs,
   kIconContracts,
   kIconCategories,
   nullptr,
--- a/layout/xul/nsMenuPopupFrame.cpp
+++ b/layout/xul/nsMenuPopupFrame.cpp
@@ -2295,24 +2295,16 @@ nsMenuPopupFrame::AttributeChanged(int32
 
 {
   nsresult rv = nsBoxFrame::AttributeChanged(aNameSpaceID, aAttribute,
                                              aModType);
 
   if (aAttribute == nsGkAtoms::left || aAttribute == nsGkAtoms::top)
     MoveToAttributePosition();
 
-#ifndef MOZ_GTK2
-  if (aAttribute == nsGkAtoms::noautohide) {
-    nsXULPopupManager* pm = nsXULPopupManager::GetInstance();
-    if (pm)
-      pm->EnableRollup(mContent, !IsNoAutoHide());
-  }
-#endif
-
   if (aAttribute == nsGkAtoms::remote) {
     // When the remote attribute changes, we need to create a new widget to
     // ensure that it has the correct compositor and transparency settings to
     // match the new value.
     EnsureWidget(true);
   }
 
   if (aAttribute == nsGkAtoms::followanchor) {
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -4482,21 +4482,17 @@ pref("font.name-list.monospace.zh-TW", "
 // 2 problems:
 // 1. The non-topmost panel steals focus from its parent window at showing.
 // 2. The parent of non-topmost panel is not activated when the panel is hidden.
 // So, we have no reasons we should use non-toplevel window for popup.
 pref("ui.panel.default_level_parent", true);
 
 pref("mousewheel.system_scroll_override_on_root_content.enabled", false);
 
-#if MOZ_WIDGET_GTK == 2
-pref("intl.ime.use_simple_context_on_password_field", true);
-#else
 pref("intl.ime.use_simple_context_on_password_field", false);
-#endif
 
 #ifdef MOZ_WIDGET_GTK
 // maximum number of fonts to substitute for a generic
 pref("gfx.font_rendering.fontconfig.max_generic_substitutions", 3);
 #endif
 
 # XP_UNIX
 #endif
--- a/testing/tools/screenshot/gdk-screenshot.cpp
+++ b/testing/tools/screenshot/gdk-screenshot.cpp
@@ -124,26 +124,19 @@ int main(int argc, char** argv)
     fprintf(stderr, "User input has been idle for %lu seconds\n", info->idle / 1000);
 
     XFree(info);
   }
 #endif
 
   GdkPixbuf* screenshot = nullptr;
   GdkWindow* window = gdk_get_default_root_window();
-#if (MOZ_WIDGET_GTK == 2)
-  screenshot = gdk_pixbuf_get_from_drawable(nullptr, window, nullptr,
-                                            0, 0, 0, 0,
-                                            gdk_screen_width(),
-                                            gdk_screen_height());
-#else
   screenshot = gdk_pixbuf_get_from_window(window, 0, 0,
                                           gdk_window_get_width(window),
                                           gdk_window_get_height(window));
-#endif
   if (!screenshot) {
     fprintf(stderr, "%s: failed to create screenshot GdkPixbuf\n", argv[0]);
     return 1;
   }
 
   GError* error = nullptr;
   if (argc > 1) {
     gdk_pixbuf_save(screenshot, argv[1], "png", &error, nullptr);
--- a/toolkit/components/remote/nsGTKRemoteService.cpp
+++ b/toolkit/components/remote/nsGTKRemoteService.cpp
@@ -99,36 +99,28 @@ void
 nsGTKRemoteService::HandleCommandsFor(GtkWidget* widget,
                                       nsIWeakReference* aWindow)
 {
   g_signal_connect(G_OBJECT(widget), "property_notify_event",
                    G_CALLBACK(HandlePropertyChange), aWindow);
 
   gtk_widget_add_events(widget, GDK_PROPERTY_CHANGE_MASK);
 
-#if (MOZ_WIDGET_GTK == 2)
-  Window window = GDK_WINDOW_XWINDOW(widget->window);
-#else
   Window window = gdk_x11_window_get_xid(gtk_widget_get_window(widget));
-#endif
   nsXRemoteService::HandleCommandsFor(window);
 }
 
 gboolean
 nsGTKRemoteService::HandlePropertyChange(GtkWidget *aWidget,
                                          GdkEventProperty *pevent,
                                          nsIWeakReference *aThis)
 {
   if (pevent->state == GDK_PROPERTY_NEW_VALUE) {
     Atom changedAtom = gdk_x11_atom_to_xatom(pevent->atom);
 
-#if (MOZ_WIDGET_GTK == 2)
-    XID window = GDK_WINDOW_XWINDOW(pevent->window);
-#else
     XID window = gdk_x11_window_get_xid(gtk_widget_get_window(aWidget));
-#endif
     return HandleNewProperty(window,
                              GDK_DISPLAY_XDISPLAY(gdk_display_get_default()),
                              pevent->time, changedAtom, aThis);
   }
   return FALSE;
 }
 
--- a/toolkit/crashreporter/client/crashreporter_linux.cpp
+++ b/toolkit/crashreporter/client/crashreporter_linux.cpp
@@ -420,21 +420,17 @@ bool UIShowCrashUI(const StringTable& fi
                                  gStrings[ST_CRASHREPORTERHEADER].c_str());
   gtk_label_set_markup(GTK_LABEL(titleLabel), markup);
   g_free(markup);
 
   GtkWidget* descriptionLabel =
     gtk_label_new(gStrings[ST_CRASHREPORTERDESCRIPTION].c_str());
   gtk_box_pack_start(GTK_BOX(vbox), descriptionLabel, TRUE, TRUE, 0);
   // force the label to line wrap
-#if (MOZ_WIDGET_GTK == 2)
-  gtk_widget_set_size_request(descriptionLabel, 400, -1);
-#else
   gtk_label_set_max_width_chars(GTK_LABEL(descriptionLabel), LABEL_MAX_CHAR_WIDTH);
-#endif
   gtk_label_set_line_wrap(GTK_LABEL(descriptionLabel), TRUE);
   gtk_label_set_selectable(GTK_LABEL(descriptionLabel), TRUE);
   gtk_misc_set_alignment(GTK_MISC(descriptionLabel), 0, 0.5);
 
   // this is honestly how they suggest you indent a section
   GtkWidget* indentBox = gtk_hbox_new(FALSE, 0);
   gtk_box_pack_start(GTK_BOX(vbox), indentBox, FALSE, FALSE, 0);
   gtk_box_pack_start(GTK_BOX(indentBox), gtk_label_new(""), FALSE, FALSE, 6);
@@ -529,21 +525,17 @@ bool UIShowCrashUI(const StringTable& fi
   g_free(dir);
   gThrobber = gtk_image_new_from_file(path);
   gtk_box_pack_start(GTK_BOX(progressBox), gThrobber, FALSE, FALSE, 0);
 
   gProgressLabel =
     gtk_label_new(gStrings[ST_REPORTPRESUBMIT].c_str());
   gtk_box_pack_start(GTK_BOX(progressBox), gProgressLabel, TRUE, TRUE, 0);
   // force the label to line wrap
-#if (MOZ_WIDGET_GTK == 2)
-  gtk_widget_set_size_request(gProgressLabel, 400, -1);
-#else
   gtk_label_set_max_width_chars(GTK_LABEL(gProgressLabel), LABEL_MAX_CHAR_WIDTH);
-#endif
   gtk_label_set_line_wrap(GTK_LABEL(gProgressLabel), TRUE);
 
   GtkWidget* buttonBox = gtk_hbutton_box_new();
   gtk_box_pack_end(GTK_BOX(vbox), buttonBox, FALSE, FALSE, 0);
   gtk_box_set_spacing(GTK_BOX(buttonBox), 6);
   gtk_button_box_set_layout(GTK_BUTTON_BOX(buttonBox), GTK_BUTTONBOX_END);
 
   gCloseButton =
--- a/toolkit/xre/glxtest.cpp
+++ b/toolkit/xre/glxtest.cpp
@@ -22,20 +22,16 @@
 #include <cstdio>
 #include <cstdlib>
 #include <unistd.h>
 #include <dlfcn.h>
 #include "nscore.h"
 #include <fcntl.h>
 #include "stdint.h"
 
-#if MOZ_WIDGET_GTK == 2
-#include <glib.h>
-#endif
-
 #ifdef __SUNPRO_CC
 #include <stdio.h>
 #endif
 
 #include "X11/Xlib.h"
 #include "X11/Xutil.h"
 
 #include "mozilla/Unused.h"
@@ -69,21 +65,16 @@ extern int glxtest_pipe;
 // the PID of the glxtest process, to pass to waitpid()
 extern pid_t glxtest_pid;
 }
 }
 
 // the write end of the pipe, which we're going to write to
 static int write_end_of_the_pipe = -1;
 
-#if MOZ_WIDGET_GTK == 2
-static int gtk_write_end_of_the_pipe = -1;
-int gtk_read_end_of_the_pipe = -1;
-#endif
-
 // C++ standard collides with C standard in that it doesn't allow casting void* to function pointer types.
 // So the work-around is to convert first to size_t.
 // http://www.trilithium.com/johan/2004/12/problem-with-dlsym/
 template<typename func_ptr_type>
 static func_ptr_type cast(void *ptr)
 {
   return reinterpret_cast<func_ptr_type>(
            reinterpret_cast<size_t>(ptr)
@@ -124,46 +115,16 @@ void glxtest()
   // we want to redirect to /dev/null stdout, stderr, and while we're at it,
   // any PR logging file descriptors. To that effect, we redirect all positive
   // file descriptors up to what open() returns here. In particular, 1 is stdout and 2 is stderr.
   int fd = open("/dev/null", O_WRONLY);
   for (int i = 1; i < fd; i++)
     dup2(fd, i);
   close(fd);
 
-#if MOZ_WIDGET_GTK == 2
-  // On Gtk+2 builds, try to get the Gtk+3 version if it's installed, and
-  // use that in nsSystemInfo for secondaryLibrary. Better safe than sorry,
-  // we want to load the Gtk+3 library in a subprocess, and since we already
-  // have such a subprocess for the GLX test, we piggy back on it.
-  void *gtk3 = dlopen("libgtk-3.so.0", RTLD_LOCAL | RTLD_LAZY);
-  if (gtk3) {
-    auto gtk_get_major_version = reinterpret_cast<guint (*)(void)>(
-      dlsym(gtk3, "gtk_get_major_version"));
-    auto gtk_get_minor_version = reinterpret_cast<guint (*)(void)>(
-      dlsym(gtk3, "gtk_get_minor_version"));
-    auto gtk_get_micro_version = reinterpret_cast<guint (*)(void)>(
-      dlsym(gtk3, "gtk_get_micro_version"));
-
-    if (gtk_get_major_version && gtk_get_minor_version &&
-        gtk_get_micro_version) {
-      // 64 bytes is going to be well enough for "GTK " followed by 3 integers
-      // separated with dots.
-      char gtkver[64];
-      int len = snprintf(gtkver, sizeof(gtkver), "GTK %u.%u.%u",
-                         gtk_get_major_version(), gtk_get_minor_version(),
-                         gtk_get_micro_version());
-      if (len > 0 && size_t(len) < sizeof(gtkver)) {
-        mozilla::Unused << write(gtk_write_end_of_the_pipe, gtkver, len);
-      }
-    }
-  }
-#endif
-
-
   if (getenv("MOZ_AVOID_OPENGL_ALTOGETHER"))
     fatal_error("The MOZ_AVOID_OPENGL_ALTOGETHER environment variable is defined");
 
   ///// Open libGL and load needed symbols /////
 #ifdef __OpenBSD__
   #define LIBGL_FILENAME "libGL.so"
 #else
   #define LIBGL_FILENAME "libGL.so.1"
@@ -298,52 +259,30 @@ void glxtest()
 /** \returns true in the child glxtest process, false in the parent process */
 bool fire_glxtest_process()
 {
   int pfd[2];
   if (pipe(pfd) == -1) {
       perror("pipe");
       return false;
   }
-#if MOZ_WIDGET_GTK == 2
-  int gtkpfd[2];
-  if (pipe(gtkpfd) == -1) {
-      perror("pipe");
-      return false;
-  }
-#endif
   pid_t pid = fork();
   if (pid < 0) {
       perror("fork");
       close(pfd[0]);
       close(pfd[1]);
-#if MOZ_WIDGET_GTK == 2
-      close(gtkpfd[0]);
-      close(gtkpfd[1]);
-#endif
       return false;
   }
   // The child exits early to avoid running the full shutdown sequence and avoid conflicting with threads
   // we have already spawned (like the profiler).
   if (pid == 0) {
       close(pfd[0]);
       write_end_of_the_pipe = pfd[1];
-#if MOZ_WIDGET_GTK == 2
-      close(gtkpfd[0]);
-      gtk_write_end_of_the_pipe = gtkpfd[1];
-#endif
       glxtest();
       close(pfd[1]);
-#if MOZ_WIDGET_GTK == 2
-      close(gtkpfd[1]);
-#endif
       _exit(0);
   }
 
   close(pfd[1]);
   mozilla::widget::glxtest_pipe = pfd[0];
   mozilla::widget::glxtest_pid = pid;
-#if MOZ_WIDGET_GTK == 2
-  close(gtkpfd[1]);
-  gtk_read_end_of_the_pipe = gtkpfd[0];
-#endif
   return false;
 }
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -3859,20 +3859,16 @@ XREMain::XRE_mainStartup(bool* aExitFlag
   }
 #endif
 
 #if defined(MOZ_WIDGET_GTK)
   // setup for private colormap.  Ideally we'd like to do this
   // in nsAppShell::Create, but we need to get in before gtk
   // has been initialized to make sure everything is running
   // consistently.
-#if (MOZ_WIDGET_GTK == 2)
-  if (CheckArg("install"))
-    gdk_rgb_set_install(TRUE);
-#endif
 
   // Set program name to the one defined in application.ini.
   {
     nsAutoCString program(gAppData->name);
     ToLowerCase(program);
     g_set_prgname(program.get());
   }
 
@@ -4067,19 +4063,16 @@ XREMain::XRE_mainStartup(bool* aExitFlag
       return 1;
     }
   }
 #endif
 #if defined(MOZ_WIDGET_GTK)
   g_set_application_name(mAppData->name);
   gtk_window_set_auto_startup_notification(false);
 
-#if (MOZ_WIDGET_GTK == 2)
-  gtk_widget_set_default_colormap(gdk_rgb_get_colormap());
-#endif /* (MOZ_WIDGET_GTK == 2) */
 #endif /* defined(MOZ_WIDGET_GTK) */
 #ifdef MOZ_X11
   // Do this after initializing GDK, or GDK will install its own handler.
   XRE_InstallX11ErrorHandler();
 #endif
 
   // Call the code to install our handler
 #ifdef MOZ_JPROF
@@ -4711,35 +4704,16 @@ XREMain::XRE_mainRun()
       NS_ERROR("failed to run appstartup");
       gLogConsoleErrors = true;
     }
   }
 
   return rv;
 }
 
-#if MOZ_WIDGET_GTK == 2
-void XRE_GlibInit()
-{
-  static bool ran_once = false;
-
-  // glib < 2.24 doesn't want g_thread_init to be invoked twice, so ensure
-  // we only do it once. No need for thread safety here, since this is invoked
-  // well before any thread is spawned.
-  if (!ran_once) {
-    // glib version < 2.36 doesn't initialize g_slice in a static initializer.
-    // Ensure this happens through g_thread_init (glib version < 2.32) or
-    // g_type_init (2.32 <= gLib version < 2.36)."
-    g_thread_init(nullptr);
-    g_type_init();
-    ran_once = true;
-  }
-}
-#endif
-
 /*
  * XRE_main - A class based main entry point used by most platforms.
  *            Note that on OSX, aAppData->xreDirectory will point to
  *            .app/Contents/Resources.
  */
 int
 XREMain::XRE_main(int argc, char* argv[], const BootstrapConfig& aConfig)
 {
@@ -4837,20 +4811,16 @@ XREMain::XRE_main(int argc, char* argv[]
 #if defined(XP_WIN)
   // Some COM settings are global to the process and must be set before any non-
   // trivial COM is run in the application. Since these settings may affect
   // stability, we should instantiate COM ASAP so that we can ensure that these
   // global settings are configured before anything can interfere.
   mozilla::mscom::MainThreadRuntime msCOMRuntime;
 #endif
 
-#if MOZ_WIDGET_GTK == 2
-  XRE_GlibInit();
-#endif
-
   // init
   bool exit = false;
   int result = XRE_mainInit(&exit);
   if (result != 0 || exit)
     return result;
 
   // startup
   result = XRE_mainStartup(&exit);
--- a/toolkit/xre/nsEmbedFunctions.cpp
+++ b/toolkit/xre/nsEmbedFunctions.cpp
@@ -510,19 +510,16 @@ XRE_InitChildProcess(int aArgc,
   CrashReporter::InitThreadAnnotationRAII annotation;
 
   gArgv = aArgv;
   gArgc = aArgc;
 
 #ifdef MOZ_X11
   XInitThreads();
 #endif
-#if MOZ_WIDGET_GTK == 2
-  XRE_GlibInit();
-#endif
 #ifdef MOZ_WIDGET_GTK
   // Setting the name here avoids the need to pass this through to gtk_init().
   g_set_prgname(aArgv[0]);
 #endif
 
 #ifdef OS_POSIX
   if (PR_GetEnv("MOZ_DEBUG_CHILD_PROCESS") ||
       PR_GetEnv("MOZ_DEBUG_CHILD_PAUSE")) {
--- a/toolkit/xre/nsNativeAppSupportUnix.cpp
+++ b/toolkit/xre/nsNativeAppSupportUnix.cpp
@@ -455,36 +455,16 @@ nsNativeAppSupportUnix::Start(bool *aRet
 
 // The dbus library is used by both nsWifiScannerDBus and BluetoothDBusService,
 // from diffrent threads. This could lead to race conditions if the dbus is not
 // initialized before making any other library calls.
 #ifdef MOZ_ENABLE_DBUS
   dbus_threads_init_default();
 #endif
 
-#if (MOZ_WIDGET_GTK == 2)
-  if (gtk_major_version < MIN_GTK_MAJOR_VERSION ||
-      (gtk_major_version == MIN_GTK_MAJOR_VERSION && gtk_minor_version < MIN_GTK_MINOR_VERSION)) {
-    GtkWidget* versionErrDialog = gtk_message_dialog_new(nullptr,
-                     GtkDialogFlags(GTK_DIALOG_MODAL |
-                                    GTK_DIALOG_DESTROY_WITH_PARENT),
-                     GTK_MESSAGE_ERROR,
-                     GTK_BUTTONS_OK,
-                     UNSUPPORTED_GTK_MSG,
-                     gtk_major_version,
-                     gtk_minor_version,
-                     MIN_GTK_MAJOR_VERSION,
-                     MIN_GTK_MINOR_VERSION);
-    gtk_dialog_run(GTK_DIALOG(versionErrDialog));
-    gtk_widget_destroy(versionErrDialog);
-    MozExpectedExit();
-    exit(0);
-  }
-#endif
-
   *aRetVal = true;
 
 #ifdef MOZ_X11
   gboolean sm_disable = FALSE;
   if (!getenv("SESSION_MANAGER")) {
     sm_disable = TRUE;
   }
 
--- a/toolkit/xre/nsX11ErrorHandler.cpp
+++ b/toolkit/xre/nsX11ErrorHandler.cpp
@@ -52,27 +52,16 @@ X11Error(Display *display, XErrorEvent *
             message.AppendInt(event->minor_code);
             break;
           }
         }
 
         XFreeExtensionList(extNames);
       }
       XCloseDisplay(tmpDisplay);
-
-#if (MOZ_WIDGET_GTK == 2)
-      // GDK2 calls XCloseDevice the devices that it opened on startup, but
-      // the XI protocol no longer ensures that the devices will still exist.
-      // If they have been removed, then a BadDevice error results.  Ignore
-      // this error.
-      if (message.EqualsLiteral("XInputExtension.4") &&
-          event->error_code == first_error + 0) {
-        return 0;
-      }
-#endif
     }
   }
 
   char buffer[BUFSIZE];
   if (message.IsEmpty()) {
     buffer[0] = '\0';
   } else {
     XGetErrorDatabaseText(display, "XRequest", message.get(), "",
--- a/widget/gtk/IMContextWrapper.cpp
+++ b/widget/gtk/IMContextWrapper.cpp
@@ -146,17 +146,17 @@ public:
     {
         AppendPrintf("{ R=0x%02X, G=0x%02X, B=0x%02X, A=0x%02X }",
                      NS_GET_R(aColor), NS_GET_G(aColor), NS_GET_B(aColor),
                      NS_GET_A(aColor));
     }
     virtual ~GetTextRangeStyleText() {};
 };
 
-const static bool kUseSimpleContextDefault = MOZ_WIDGET_GTK == 2;
+const static bool kUseSimpleContextDefault = false;
 
 /******************************************************************************
  * IMContextWrapper
  ******************************************************************************/
 
 IMContextWrapper* IMContextWrapper::sLastFocusedContext = nullptr;
 bool IMContextWrapper::sUseSimpleContext;
 
@@ -427,22 +427,17 @@ IMContextWrapper::OnDestroyWindow(nsWind
 // find the signal handlers and remove them.
 //
 // GtkIMContextXIMs share XOpenIM connections and display closed signal
 // handlers (where possible).
 
 void
 IMContextWrapper::PrepareToDestroyContext(GtkIMContext* aContext)
 {
-#if (MOZ_WIDGET_GTK == 2)
-    GtkIMMulticontext *multicontext = GTK_IM_MULTICONTEXT(aContext);
-    GtkIMContext *slave = multicontext->slave;
-#else
     GtkIMContext *slave = nullptr; //TODO GTK3
-#endif
     if (!slave) {
         return;
     }
 
     GType slaveType = G_TYPE_FROM_INSTANCE(slave);
     const gchar *im_type_name = g_type_name(slaveType);
     if (strcmp(im_type_name, "GtkIMContextIIIM") == 0) {
         // Add a reference to prevent the IIIM module from being unloaded
--- a/widget/gtk/NativeKeyBindings.cpp
+++ b/widget/gtk/NativeKeyBindings.cpp
@@ -355,23 +355,18 @@ NativeKeyBindings::GetEditCommandsIntern
                                            guint aKeyval)
 {
   guint modifiers =
     static_cast<GdkEventKey*>(aEvent.mNativeKeyEvent)->state;
 
   gCurrentCommands = &aCommands;
 
   gHandled = false;
-#if (MOZ_WIDGET_GTK == 2)
-  gtk_bindings_activate(GTK_OBJECT(mNativeTarget),
-                        aKeyval, GdkModifierType(modifiers));
-#else
   gtk_bindings_activate(G_OBJECT(mNativeTarget),
                         aKeyval, GdkModifierType(modifiers));
-#endif
 
   gCurrentCommands = nullptr;
 
   MOZ_ASSERT(!gHandled || !aCommands.IsEmpty());
 
   return gHandled;
 }
 
--- a/widget/gtk/gtkdrawing.h
+++ b/widget/gtk/gtkdrawing.h
@@ -14,22 +14,16 @@
 
 #ifndef _GTK_DRAWING_H_
 #define _GTK_DRAWING_H_
 
 #include <gdk/gdk.h>
 #include <gtk/gtk.h>
 #include <algorithm>
 
-#if (MOZ_WIDGET_GTK == 2)
-#ifdef __cplusplus
-extern "C" {
-#endif /* __cplusplus */
-#endif
-
 /*** type definitions ***/
 typedef struct {
   guint8 active;
   guint8 focused;
   guint8 inHover;
   guint8 disabled;
   guint8 isDefault;
   guint8 canDefault;
@@ -330,48 +324,32 @@ void moz_gtk_refresh();
 /**
  * Perform cleanup of the drawing library. You should call this function
  * when your program exits, or you no longer need the library.
  *
  * returns: MOZ_GTK_SUCCESS if there was no error, an error code otherwise
  */
 gint moz_gtk_shutdown();
 
-#if (MOZ_WIDGET_GTK == 2)
-/**
- * Retrieves the colormap to use for drawables passed to moz_gtk_widget_paint.
- */
-GdkColormap* moz_gtk_widget_get_colormap();
-#endif
-
 /*** Widget drawing ***/
-#if (MOZ_WIDGET_GTK == 2)
 /**
  * Paint a widget in the current theme.
  * widget:    a constant giving the widget to paint
  * drawable:  the drawable to paint to;
  *            it's colormap must be moz_gtk_widget_get_colormap().
  * rect:      the bounding rectangle for the widget
- * cliprect:  a clipprect rectangle for this painting operation
  * state:     the state of the widget.  ignored for some widgets.
  * flags:     widget-dependant flags; see the WidgetNodeType definition.
  * direction: the text direction, to draw the widget correctly LTR and RTL.
  */
 gint
-moz_gtk_widget_paint(WidgetNodeType widget, GdkDrawable* drawable,
-                     GdkRectangle* rect, GdkRectangle* cliprect,
-                     GtkWidgetState* state, gint flags,
-                     GtkTextDirection direction);
-#else
-gint
 moz_gtk_widget_paint(WidgetNodeType widget, cairo_t *cr,
                      GdkRectangle* rect,
                      GtkWidgetState* state, gint flags,
                      GtkTextDirection direction);
-#endif
 
 
 /*** Widget metrics ***/
 /**
  * Get the border size of a widget
  * left/right:  [OUT] the widget's left/right border
  * top/bottom:  [OUT] the widget's top/bottom border
  * direction:   the text direction for the widget.  Callers depend on this
@@ -569,15 +547,9 @@ gint moz_gtk_get_menu_separator_height(g
 gint moz_gtk_splitter_get_metrics(gint orientation, gint* size);
 
 /**
  * Get the YTHICKNESS of a tab (notebook extension).
  */
 gint
 moz_gtk_get_tab_thickness(WidgetNodeType aNodeType);
 
-#if (MOZ_WIDGET_GTK == 2)
-#ifdef __cplusplus
-}
-#endif /* __cplusplus */
 #endif
-
-#endif
--- a/widget/gtk/mozcontainer.cpp
+++ b/widget/gtk/mozcontainer.cpp
@@ -345,39 +345,25 @@ moz_container_realize (GtkWidget *widget
         attributes.x = allocation.x;
         attributes.y = allocation.y;
         attributes.width = allocation.width;
         attributes.height = allocation.height;
         attributes.wclass = GDK_INPUT_OUTPUT;
         attributes.visual = gtk_widget_get_visual (widget);
         attributes.window_type = GDK_WINDOW_CHILD;
 
-#if (MOZ_WIDGET_GTK == 2)
-        attributes.colormap = gtk_widget_get_colormap (widget);
-        attributes_mask |= GDK_WA_COLORMAP;
-#endif
-
         window = gdk_window_new (parent, &attributes, attributes_mask);
         gdk_window_set_user_data (window, widget);
-#if (MOZ_WIDGET_GTK == 2)
-        /* TODO GTK3? */
-        /* set the back pixmap to None so that you don't end up with the gtk
-           default which is BlackPixel */
-        gdk_window_set_back_pixmap (window, NULL, FALSE);
-#endif
     } else {
         window = parent;
         g_object_ref (window);
     }
 
     gtk_widget_set_window (widget, window);
 
-#if (MOZ_WIDGET_GTK == 2)
-    widget->style = gtk_style_attach (widget->style, widget->window);
-#endif
 }
 
 void
 moz_container_size_allocate (GtkWidget     *widget,
                              GtkAllocation *allocation)
 {
     MozContainer   *container;
     GList          *tmp_list;
--- a/widget/gtk/nsDragService.cpp
+++ b/widget/gtk/nsDragService.cpp
@@ -102,22 +102,18 @@ nsDragService::nsDragService()
 {
     // We have to destroy the hidden widget before the event loop stops
     // running.
     nsCOMPtr<nsIObserverService> obsServ =
         mozilla::services::GetObserverService();
     obsServ->AddObserver(this, "quit-application", false);
 
     // our hidden source widget
-#if (MOZ_WIDGET_GTK == 2)
-    mHiddenWidget = gtk_window_new(GTK_WINDOW_POPUP);
-#else
     // Using an offscreen window works around bug 983843.
     mHiddenWidget = gtk_offscreen_window_new();
-#endif
     // make sure that the widget is realized so that
     // we can use it as a drag source.
     gtk_widget_realize(mHiddenWidget);
     // hook up our internal signals so that we can get some feedback
     // from our drag source
     g_signal_connect(mHiddenWidget, "drag_begin",
                      G_CALLBACK(invisibleSourceDragBegin), this);
     g_signal_connect(mHiddenWidget, "drag_data_get",
@@ -430,52 +426,16 @@ nsDragService::SetAlphaPixmap(SourceSurf
 {
     GdkScreen* screen = gtk_widget_get_screen(mHiddenWidget);
 
     // Transparent drag icons need, like a lot of transparency-related things,
     // a compositing X window manager
     if (!gdk_screen_is_composited(screen))
       return false;
 
-#if (MOZ_WIDGET_GTK == 2)
-    GdkColormap* alphaColormap = gdk_screen_get_rgba_colormap(screen);
-    if (!alphaColormap)
-      return false;
-
-    GdkPixmap* pixmap = gdk_pixmap_new(nullptr, dragRect.width, dragRect.height,
-                                       gdk_colormap_get_visual(alphaColormap)->depth);
-    if (!pixmap)
-      return false;
-
-    gdk_drawable_set_colormap(GDK_DRAWABLE(pixmap), alphaColormap);
-
-    // Make a DrawTarget wrapped around the pixmap to render on
-    RefPtr<DrawTarget> dt =
-         nsWindow::GetDrawTargetForGdkDrawable(GDK_DRAWABLE(pixmap),
-                                               IntSize(dragRect.width,
-                                                       dragRect.height));
-    if (!dt)
-      return false;
-
-    // Clear it...
-    dt->ClearRect(Rect(0, 0, dragRect.width, dragRect.height));
-
-    // ...and paint the drag image with translucency
-    dt->DrawSurface(aSurface,
-                    Rect(0, 0, dragRect.width, dragRect.height),
-                    Rect(0, 0, dragRect.width, dragRect.height),
-                    DrawSurfaceOptions(),
-                    DrawOptions(DRAG_IMAGE_ALPHA_LEVEL, CompositionOp::OP_SOURCE));
-
-    // The drag transaction addrefs the pixmap, so we can just unref it from us here
-    gtk_drag_set_icon_pixmap(aContext, alphaColormap, pixmap, nullptr,
-                             aXOffset, aYOffset);
-    g_object_unref(pixmap);
-    return true;
-#else
 #ifdef cairo_image_surface_create
 #error "Looks like we're including Mozilla's cairo instead of system cairo"
 #endif
     // Prior to GTK 3.9.12, cairo surfaces passed into gtk_drag_set_icon_surface
     // had their shape information derived from the alpha channel and used with
     // the X SHAPE extension instead of being displayed as an ARGB window.
     // See bug 1249604.
     if (gtk_check_version(3, 9, 12))
@@ -513,17 +473,16 @@ nsDragService::SetAlphaPixmap(SourceSurf
     if (sCairoSurfaceSetDeviceScalePtr) {
         gint scale = ScreenHelperGTK::GetGTKMonitorScaleFactor();
         sCairoSurfaceSetDeviceScalePtr(surf, scale, scale);
     }
 
     gtk_drag_set_icon_surface(aContext, surf);
     cairo_surface_destroy(surf);
     return true;
-#endif
 }
 
 NS_IMETHODIMP
 nsDragService::StartDragSession()
 {
     MOZ_LOG(sDragLm, LogLevel::Debug, ("nsDragService::StartDragSession"));
     return nsBaseDragService::StartDragSession();
 }
--- a/widget/gtk/nsNativeThemeGTK.cpp
+++ b/widget/gtk/nsNativeThemeGTK.cpp
@@ -727,60 +727,16 @@ nsNativeThemeGTK::GetGtkWidgetAndState(u
     break;
   default:
     return false;
   }
 
   return true;
 }
 
-#if (MOZ_WIDGET_GTK == 2)
-class ThemeRenderer : public gfxGdkNativeRenderer {
-public:
-  ThemeRenderer(GtkWidgetState aState, WidgetNodeType aGTKWidgetType,
-                gint aFlags, GtkTextDirection aDirection,
-                const GdkRectangle& aGDKRect, const GdkRectangle& aGDKClip)
-    : mState(aState), mGTKWidgetType(aGTKWidgetType), mFlags(aFlags),
-      mDirection(aDirection), mGDKRect(aGDKRect), mGDKClip(aGDKClip) {}
-  nsresult DrawWithGDK(GdkDrawable * drawable, gint offsetX, gint offsetY,
-                       GdkRectangle * clipRects, uint32_t numClipRects);
-private:
-  GtkWidgetState mState;
-  WidgetNodeType mGTKWidgetType;
-  gint mFlags;
-  GtkTextDirection mDirection;
-  const GdkRectangle& mGDKRect;
-  const GdkRectangle& mGDKClip;
-};
-
-nsresult
-ThemeRenderer::DrawWithGDK(GdkDrawable * drawable, gint offsetX, 
-        gint offsetY, GdkRectangle * clipRects, uint32_t numClipRects)
-{
-  GdkRectangle gdk_rect = mGDKRect;
-  gdk_rect.x += offsetX;
-  gdk_rect.y += offsetY;
-
-  GdkRectangle gdk_clip = mGDKClip;
-  gdk_clip.x += offsetX;
-  gdk_clip.y += offsetY;
-
-  GdkRectangle surfaceRect;
-  surfaceRect.x = 0;
-  surfaceRect.y = 0;
-  gdk_drawable_get_size(drawable, &surfaceRect.width, &surfaceRect.height);
-  gdk_rectangle_intersect(&gdk_clip, &surfaceRect, &gdk_clip);
-  
-  NS_ASSERTION(numClipRects == 0, "We don't support clipping!!!");
-  moz_gtk_widget_paint(mGTKWidgetType, drawable, &gdk_rect, &gdk_clip,
-                       &mState, mFlags, mDirection);
-
-  return NS_OK;
-}
-#else
 class SystemCairoClipper : public ClipExporter {
 public:
   explicit SystemCairoClipper(cairo_t* aContext) : mContext(aContext)
   {
   }
 
   void
   BeginClip(const Matrix& aTransform) override
@@ -1019,17 +975,16 @@ DrawThemeWithCairo(gfxContext* aContext,
       }
 
       if (surf) {
         cairo_surface_destroy(surf);
       }
     }
   }
 }
-#endif
 
 bool
 nsNativeThemeGTK::GetExtraSizeForWidget(nsIFrame* aFrame, uint8_t aWidgetType,
                                         nsIntMargin* aExtra)
 {
   *aExtra = nsIntMargin(0,0,0,0);
   // Allow an extra one pixel above and below the thumb for certain
   // GTK2 themes (Ximian Industrial, Bluecurve, Misty, at least);
@@ -1167,52 +1122,20 @@ nsNativeThemeGTK::DrawWidgetBackground(g
   GdkRectangle gdk_rect = {-drawingRect.x/scaleFactor,
                            -drawingRect.y/scaleFactor,
                            widgetRect.width/scaleFactor,
                            widgetRect.height/scaleFactor};
 
   // translate everything so (0,0) is the top left of the drawingRect
   gfxPoint origin = rect.TopLeft() + drawingRect.TopLeft();
 
-#if (MOZ_WIDGET_GTK == 2)
-  gfxContextAutoSaveRestore autoSR(ctx);
-  gfxMatrix matrix;
-  if (!snapped) { // else rects are in device coords
-    matrix = ctx->CurrentMatrixDouble();
-  }
-  matrix.Translate(origin);
-  matrix.Scale(scaleFactor, scaleFactor); // Draw in GDK coords
-  ctx->SetMatrixDouble(matrix);
-
-  // The gdk_clip is just advisory here, meaning "you don't
-  // need to draw outside this rect if you don't feel like it!"
-  GdkRectangle gdk_clip = {0, 0, drawingRect.width, drawingRect.height};
-
-  ThemeRenderer renderer(state, gtkWidgetType, flags, direction,
-                         gdk_rect, gdk_clip);
-
-  // Some themes (e.g. Clearlooks) just don't clip properly to any
-  // clip rect we provide, so we cannot advertise support for clipping within
-  // the widget bounds.
-  uint32_t rendererFlags = 0;
-  if (transparency == eOpaque) {
-    rendererFlags |= gfxGdkNativeRenderer::DRAW_IS_OPAQUE;
-  }
-
-  // GtkStyles (used by the widget drawing backend) are created for a
-  // particular colormap/visual.
-  GdkColormap* colormap = moz_gtk_widget_get_colormap();
-
-  renderer.Draw(ctx, drawingRect.Size(), rendererFlags, colormap);
-#else 
   DrawThemeWithCairo(ctx, aContext->GetDrawTarget(),
                      state, gtkWidgetType, flags, direction, scaleFactor,
                      snapped, ToPoint(origin), drawingRect.Size(),
                      gdk_rect, transparency);
-#endif
 
   if (!safeState) {
     gdk_flush();
     gLastGdkError = gdk_error_trap_pop ();
 
     if (gLastGdkError) {
 #ifdef DEBUG
       printf("GTK theme failed for widget type %d, error was %d, state was "
@@ -1963,20 +1886,16 @@ nsNativeThemeGTK::ThemeNeedsComboboxDrop
   return false;
 }
 
 nsITheme::Transparency
 nsNativeThemeGTK::GetWidgetTransparency(nsIFrame* aFrame, uint8_t aWidgetType)
 {
   switch (aWidgetType) {
   // These widgets always draw a default background.
-#if (MOZ_WIDGET_GTK == 2)
-  case NS_THEME_TOOLBAR:
-  case NS_THEME_MENUBAR:
-#endif
   case NS_THEME_MENUPOPUP:
   case NS_THEME_WINDOW:
   case NS_THEME_DIALOG:
     return eOpaque;
   case NS_THEME_SCROLLBAR_VERTICAL:
   case NS_THEME_SCROLLBAR_HORIZONTAL:
 #ifdef MOZ_WIDGET_GTK
     // Make scrollbar tracks opaque on the window's scroll frame to prevent
@@ -1985,17 +1904,13 @@ nsNativeThemeGTK::GetWidgetTransparency(
           aFrame->PresContext()->IsRootContentDocument() &&
           IsFrameContentNodeInNamespace(aFrame, kNameSpaceID_XUL)))
       return eTransparent;
 #endif
     return eOpaque;
   // Tooltips use gtk_paint_flat_box() on Gtk2
   // but are shaped on Gtk3
   case NS_THEME_TOOLTIP:
-#if (MOZ_WIDGET_GTK == 2)
-    return eOpaque;
-#else
     return eTransparent;
-#endif
   }
 
   return eUnknownTransparency;
 }
--- a/widget/gtk/nsPrintDialogGTK.cpp
+++ b/widget/gtk/nsPrintDialogGTK.cpp
@@ -52,21 +52,17 @@ ShowCustomDialog(GtkComboBox *changed_bo
        do_GetService(NS_STRINGBUNDLE_CONTRACTID);
 
   nsCOMPtr<nsIStringBundle> printBundle;
   bundleSvc->CreateBundle("chrome://global/locale/printdialog.properties", getter_AddRefs(printBundle));
   nsAutoString intlString;
 
   printBundle->GetStringFromName("headerFooterCustom", intlString);
   GtkWidget* prompt_dialog = gtk_dialog_new_with_buttons(NS_ConvertUTF16toUTF8(intlString).get(), printDialog,
-#if (MOZ_WIDGET_GTK == 2)
-                                                         (GtkDialogFlags)(GTK_DIALOG_MODAL | GTK_DIALOG_NO_SEPARATOR),
-#else
                                                          (GtkDialogFlags)(GTK_DIALOG_MODAL),
-#endif
                                                          GTK_STOCK_CANCEL, GTK_RESPONSE_REJECT,
                                                          GTK_STOCK_OK, GTK_RESPONSE_ACCEPT,
                                                          nullptr);
   gtk_dialog_set_default_response(GTK_DIALOG(prompt_dialog), GTK_RESPONSE_ACCEPT);
   gtk_dialog_set_alternative_button_order(GTK_DIALOG(prompt_dialog),
                                           GTK_RESPONSE_ACCEPT,
                                           GTK_RESPONSE_REJECT,
                                           -1);
@@ -462,33 +458,25 @@ nsPrintDialogWidgetGTK::ExportSettings(n
   if (settings)
     g_object_unref(settings);
   return NS_OK;
 }
 
 GtkWidget*
 nsPrintDialogWidgetGTK::ConstructHeaderFooterDropdown(const char16_t *currentString)
 {
-#if (MOZ_WIDGET_GTK == 2)
-  GtkWidget* dropdown = gtk_combo_box_new_text();
-#else
   GtkWidget* dropdown = gtk_combo_box_text_new();
-#endif
   const char hf_options[][22] = {"headerFooterBlank", "headerFooterTitle",
                                  "headerFooterURL", "headerFooterDate",
                                  "headerFooterPage", "headerFooterPageTotal",
                                  "headerFooterCustom"};
 
   for (unsigned int i = 0; i < ArrayLength(hf_options); i++) {
-#if (MOZ_WIDGET_GTK == 2)
-    gtk_combo_box_append_text(GTK_COMBO_BOX(dropdown), GetUTF8FromBundle(hf_options[i]).get());
-#else
-    gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(dropdown), nullptr, 
+    gtk_combo_box_text_append(GTK_COMBO_BOX_TEXT(dropdown), nullptr,
                               GetUTF8FromBundle(hf_options[i]).get());
-#endif
   }
 
   bool shouldBeCustom = true;
   NS_ConvertUTF16toUTF8 currentStringUTF8(currentString);
 
   for (unsigned int i = 0; i < ArrayLength(header_footer_tags); i++) {
     if (!strcmp(currentStringUTF8.get(), header_footer_tags[i])) {
       gtk_combo_box_set_active(GTK_COMBO_BOX(dropdown), i);
--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -45,25 +45,19 @@
 #endif /* MOZ_WAYLAND */
 
 #ifdef MOZ_X11
 #include <gdk/gdkx.h>
 #include <X11/Xatom.h>
 #include <X11/extensions/XShm.h>
 #include <X11/extensions/shape.h>
 #include <gdk/gdkkeysyms-compat.h>
-#if (MOZ_WIDGET_GTK == 2)
-#include "gtk2xtbin.h"
-#endif
 #endif /* MOZ_X11 */
 
 #include <gdk/gdkkeysyms.h>
-#if (MOZ_WIDGET_GTK == 2)
-#include <gtk/gtkprivate.h>
-#endif
 
 #if defined(MOZ_WAYLAND)
 #include <gdk/gdkwayland.h>
 #endif
 
 #include "nsGkAtoms.h"
 
 #ifdef MOZ_ENABLE_STARTUP_NOTIFICATION
@@ -175,23 +169,18 @@ static GdkCursor *get_gtk_cursor(nsCurso
 static GdkWindow *get_inner_gdk_window (GdkWindow *aWindow,
                                         gint x, gint y,
                                         gint *retx, gint *rety);
 
 static int    is_parent_ungrab_enter(GdkEventCrossing *aEvent);
 static int    is_parent_grab_leave(GdkEventCrossing *aEvent);
 
 /* callbacks from widgets */
-#if (MOZ_WIDGET_GTK == 2)
-static gboolean expose_event_cb           (GtkWidget *widget,
-                                           GdkEventExpose *event);
-#else
 static gboolean expose_event_cb           (GtkWidget *widget,
                                            cairo_t *rect);
-#endif
 static gboolean configure_event_cb        (GtkWidget *widget,
                                            GdkEventConfigure *event);
 static void     container_unrealize_cb    (GtkWidget *widget);
 static void     size_allocate_cb          (GtkWidget *widget,
                                            GtkAllocation *allocation);
 static gboolean delete_event_cb           (GtkWidget *widget,
                                            GdkEventAny *event);
 static gboolean enter_notify_event_cb     (GtkWidget *widget,
@@ -385,17 +374,17 @@ static GtkWidget *gInvisibleContainer = 
 
 // Sometimes this actually also includes the state of the modifier keys, but
 // only the button state bits are used.
 static guint gButtonState;
 
 static inline int32_t
 GetBitmapStride(int32_t width)
 {
-#if defined(MOZ_X11) || (MOZ_WIDGET_GTK == 2)
+#if defined(MOZ_X11)
   return (width+7)/8;
 #else
   return cairo_format_stride_for_width(CAIRO_FORMAT_A1, width);
 #endif
 }
 
 static inline bool TimestampIsNewerThan(guint32 a, guint32 b)
 {
@@ -1981,21 +1970,17 @@ gdk_window_flash(GdkWindow *    aGdkWind
   gint         x;
   gint         y;
   gint         width;
   gint         height;
   guint        i;
   GdkGC *      gc = 0;
   GdkColor     white;
 
-#if (MOZ_WIDGET_GTK == 2)
-  gdk_window_get_geometry(aGdkWindow,nullptr,nullptr,&width,&height,nullptr);
-#else
   gdk_window_get_geometry(aGdkWindow,nullptr,nullptr,&width,&height);
-#endif
 
   gdk_window_get_origin (aGdkWindow,
                          &x,
                          &y);
 
   gc = gdk_gc_new(gdk_get_default_root_window());
 
   white.pixel = WhitePixel(gdk_display,DefaultScreen(gdk_display));
@@ -2029,40 +2014,16 @@ gdk_window_flash(GdkWindow *    aGdkWind
   gdk_gc_destroy(gc);
 
   gdk_region_offset(aRegion, -x, -y);
 }
 #endif /* MOZ_X11 */
 #endif // DEBUG
 #endif
 
-#if (MOZ_WIDGET_GTK == 2)
-static bool
-ExtractExposeRegion(LayoutDeviceIntRegion& aRegion, GdkEventExpose* aEvent)
-{
-  GdkRectangle* rects;
-  gint nrects;
-  gdk_region_get_rectangles(aEvent->region, &rects, &nrects);
-
-  if (nrects > MAX_RECTS_IN_REGION) {
-      // Just use the bounding box
-      rects[0] = aEvent->area;
-      nrects = 1;
-  }
-
-  for (GdkRectangle* r = rects; r < rects + nrects; r++) {
-      aRegion.Or(aRegion, LayoutDeviceIntRect(r->x, r->y, r->width, r->height));
-      LOGDRAW(("\t%d %d %d %d\n", r->x, r->y, r->width, r->height));
-  }
-
-  g_free(rects);
-  return true;
-}
-
-#else
 # ifdef cairo_copy_clip_rectangle_list
 #  error "Looks like we're including Mozilla's cairo instead of system cairo"
 # endif
 static bool
 ExtractExposeRegion(LayoutDeviceIntRegion& aRegion, cairo_t* cr)
 {
   cairo_rectangle_list_t* rects = cairo_copy_clip_rectangle_list(cr);
   if (rects->status != CAIRO_STATUS_SUCCESS) {
@@ -2074,25 +2035,19 @@ ExtractExposeRegion(LayoutDeviceIntRegio
       const cairo_rectangle_t& r = rects->rectangles[i];
       aRegion.Or(aRegion, LayoutDeviceIntRect::Truncate(r.x, r.y, r.width, r.height));
       LOGDRAW(("\t%f %f %f %f\n", r.x, r.y, r.width, r.height));
   }
 
   cairo_rectangle_list_destroy(rects);
   return true;
 }
-#endif
-
-#if (MOZ_WIDGET_GTK == 2)
-gboolean
-nsWindow::OnExposeEvent(GdkEventExpose *aEvent)
-#else
+
 gboolean
 nsWindow::OnExposeEvent(cairo_t *cr)
-#endif
 {
     // Send any pending resize events so that layout can update.
     // May run event loop.
     MaybeDispatchResized();
 
     if (mIsDestroyed) {
         return FALSE;
     }
@@ -2101,21 +2056,17 @@ nsWindow::OnExposeEvent(cairo_t *cr)
     if (!mGdkWindow || mIsFullyObscured || !mHasMappedToplevel)
         return FALSE;
 
     nsIWidgetListener *listener = GetListener();
     if (!listener)
         return FALSE;
 
     LayoutDeviceIntRegion exposeRegion;
-#if (MOZ_WIDGET_GTK == 2)
-    if (!ExtractExposeRegion(exposeRegion, aEvent)) {
-#else
     if (!ExtractExposeRegion(exposeRegion, cr)) {
-#endif
         return FALSE;
     }
 
     gint scale = GdkScaleFactor();
     LayoutDeviceIntRegion region = exposeRegion;
     region.ScaleRoundOut(scale, scale);
 
     if (GetLayerManager()->AsKnowsCompositor() && mCompositorSession) {
@@ -2309,29 +2260,21 @@ nsWindow::OnExposeEvent(cairo_t *cr)
 
 #endif // MOZ_X11
 
     EndRemoteDrawingInRegion(dt, region);
 
     listener->DidPaintWindow();
 
     // Synchronously flush any new dirty areas
-#if (MOZ_WIDGET_GTK == 2)
-    GdkRegion* dirtyArea = gdk_window_get_update_area(mGdkWindow);
-#else
     cairo_region_t* dirtyArea = gdk_window_get_update_area(mGdkWindow);
-#endif
 
     if (dirtyArea) {
         gdk_window_invalidate_region(mGdkWindow, dirtyArea, false);
-#if (MOZ_WIDGET_GTK == 2)
-        gdk_region_destroy(dirtyArea);
-#else
         cairo_region_destroy(dirtyArea);
-#endif
         gdk_window_process_updates(mGdkWindow, false);
     }
 
     // check the return value!
     return TRUE;
 }
 
 void
@@ -3555,31 +3498,19 @@ CreateGdkWindow(GdkWindow *parent, GtkWi
     attributes.event_mask = kEvents;
 
     attributes.width = 1;
     attributes.height = 1;
     attributes.wclass = GDK_INPUT_OUTPUT;
     attributes.visual = gtk_widget_get_visual(widget);
     attributes.window_type = GDK_WINDOW_CHILD;
 
-#if (MOZ_WIDGET_GTK == 2)
-    attributes_mask |= GDK_WA_COLORMAP;
-    attributes.colormap = gtk_widget_get_colormap(widget);
-#endif
-
     GdkWindow *window = gdk_window_new(parent, &attributes, attributes_mask);
     gdk_window_set_user_data(window, widget);
 
-// GTK3 TODO?
-#if (MOZ_WIDGET_GTK == 2)
-    /* set the default pixmap to None so that you don't end up with the
-       gtk default which is BlackPixel. */
-    gdk_window_set_back_pixmap(window, nullptr, FALSE);
-#endif
-
     return window;
 }
 
 nsresult
 nsWindow::Create(nsIWidget* aParent,
                  nsNativeWidget aNativeParent,
                  const LayoutDeviceIntRect& aRect,
                  nsWidgetInitData* aInitData)
@@ -3683,23 +3614,18 @@ nsWindow::Create(nsIWidget* aParent,
 
         // We need to select an ARGB visual here instead of in
         // SetTransparencyMode() because it has to be done before the
         // widget is realized.  An ARGB visual is only useful if we
         // are on a compositing window manager.
         if (useAlphaVisual) {
             GdkScreen *screen = gtk_widget_get_screen(mShell);
             if (gdk_screen_is_composited(screen)) {
-#if (MOZ_WIDGET_GTK == 2)
-                GdkColormap *colormap = gdk_screen_get_rgba_colormap(screen);
-                gtk_widget_set_colormap(mShell, colormap);
-#else
                 GdkVisual *visual = gdk_screen_get_rgba_visual(screen);
                 gtk_widget_set_visual(mShell, visual);
-#endif
             }
         }
 
         // We only move a general managed toplevel window if someone has
         // actually placed the window somewhere.  If no placement has taken
         // place, we just let the window manager Do The Right Thing.
         NativeResize();
 
@@ -3857,29 +3783,21 @@ nsWindow::Create(nsIWidget* aParent,
             if (aInitData->mNoAutoHide) {
                 gint wmd = ConvertBorderStyles(mBorderStyle);
                 if (wmd != -1)
                   gdk_window_set_decorations(mGdkWindow, (GdkWMDecoration) wmd);
             }
 
             // If the popup ignores mouse events, set an empty input shape.
             if (aInitData->mMouseTransparent) {
-#if (MOZ_WIDGET_GTK == 2)
-              GdkRectangle rect = { 0, 0, 0, 0 };
-              GdkRegion *region = gdk_region_rectangle(&rect);
-
-              gdk_window_input_shape_combine_region(mGdkWindow, region, 0, 0);
-              gdk_region_destroy(region);
-#else
               cairo_rectangle_int_t rect = { 0, 0, 0, 0 };
               cairo_region_t *region = cairo_region_create_rectangle(&rect);
 
               gdk_window_input_shape_combine_region(mGdkWindow, region, 0, 0);
               cairo_region_destroy(region);
-#endif
             }
         }
     }
         break;
 
     case eWindowType_plugin:
     case eWindowType_plugin_ipc_chrome:
     case eWindowType_plugin_ipc_content:
@@ -3970,23 +3888,18 @@ nsWindow::Create(nsIWidget* aParent,
         g_signal_connect(mContainer, "hierarchy-changed",
                          G_CALLBACK(hierarchy_changed_cb), nullptr);
         g_signal_connect(mContainer, "notify::scale-factor",
                          G_CALLBACK(scale_changed_cb), nullptr);
         // Initialize mHasMappedToplevel.
         hierarchy_changed_cb(GTK_WIDGET(mContainer), nullptr);
         // Expose, focus, key, and drag events are sent even to GTK_NO_WINDOW
         // widgets.
-#if (MOZ_WIDGET_GTK == 2)
-        g_signal_connect(mContainer, "expose_event",
-                         G_CALLBACK(expose_event_cb), nullptr);
-#else
         g_signal_connect(G_OBJECT(mContainer), "draw",
                          G_CALLBACK(expose_event_cb), nullptr);
-#endif
         g_signal_connect(mContainer, "focus_in_event",
                          G_CALLBACK(focus_in_event_cb), nullptr);
         g_signal_connect(mContainer, "focus_out_event",
                          G_CALLBACK(focus_out_event_cb), nullptr);
         g_signal_connect(mContainer, "key_press_event",
                          G_CALLBACK(key_press_event_cb), nullptr);
         g_signal_connect(mContainer, "key_release_event",
                          G_CALLBACK(key_release_event_cb), nullptr);
@@ -4028,20 +3941,16 @@ nsWindow::Create(nsIWidget* aParent,
     } else if (!mIMContext) {
         nsWindow *container = GetContainerWindow();
         if (container) {
             mIMContext = container->mIMContext;
         }
     }
 
     if (eventWidget) {
-#if (MOZ_WIDGET_GTK == 2)
-        // Don't let GTK mess with the shapes of our GdkWindows
-        GTK_PRIVATE_SET_FLAG(eventWidget, GTK_HAS_SHAPE_MASK);
-#endif
 
         // These events are sent to the owning widget of the relevant window
         // and propagate up to the first widget that handles the events, so we
         // need only connect on mShell, if it exists, to catch events on its
         // window and windows of mContainer.
         g_signal_connect(eventWidget, "enter-notify-event",
                          G_CALLBACK(enter_notify_event_cb), nullptr);
         g_signal_connect(eventWidget, "leave-notify-event",
@@ -4554,37 +4463,25 @@ nsWindow::SetWindowClipRegion(const nsTA
     if (IsWindowClipRegionEqual(*newRects))
         return NS_OK;
 
     StoreWindowClipRegion(*newRects);
 
     if (!mGdkWindow)
         return NS_OK;
 
-#if (MOZ_WIDGET_GTK == 2)
-    GdkRegion *region = gdk_region_new(); // aborts on OOM
-    for (uint32_t i = 0; i < newRects->Length(); ++i) {
-        const LayoutDeviceIntRect& r = newRects->ElementAt(i);
-        GdkRectangle rect = { r.x, r.y, r.width, r.height };
-        gdk_region_union_with_rect(region, &rect);
-    }
-
-    gdk_window_shape_combine_region(mGdkWindow, region, 0, 0);
-    gdk_region_destroy(region);
-#else
     cairo_region_t *region = cairo_region_create();
     for (uint32_t i = 0; i < newRects->Length(); ++i) {
         const LayoutDeviceIntRect& r = newRects->ElementAt(i);
         cairo_rectangle_int_t rect = { r.x, r.y, r.width, r.height };
         cairo_region_union_rectangle(region, &rect);
     }
 
     gdk_window_shape_combine_region(mGdkWindow, region, 0, 0);
     cairo_region_destroy(region);
-#endif
 
     return NS_OK;
 }
 
 void
 nsWindow::ResizeTransparencyBitmap()
 {
     if (!mTransparencyBitmap)
@@ -4683,41 +4580,29 @@ nsWindow::ApplyTransparencyBitmap()
                                               mTransparencyBitmap,
                                               mTransparencyBitmapWidth,
                                               mTransparencyBitmapHeight);
     XShapeCombineMask(xDisplay, xDrawable,
                       ShapeBounding, 0, 0,
                       maskPixmap, ShapeSet);
     XFreePixmap(xDisplay, maskPixmap);
 #else
-#if (MOZ_WIDGET_GTK == 2)
-    gtk_widget_reset_shapes(mShell);
-    GdkBitmap* maskBitmap = gdk_bitmap_create_from_data(mGdkWindow,
-            mTransparencyBitmap,
-            mTransparencyBitmapWidth, mTransparencyBitmapHeight);
-    if (!maskBitmap)
-        return;
-
-    gtk_widget_shape_combine_mask(mShell, maskBitmap, 0, 0);
-    g_object_unref(maskBitmap);
-#else
     cairo_surface_t *maskBitmap;
     maskBitmap = cairo_image_surface_create_for_data((unsigned char*)mTransparencyBitmap,
                                                      CAIRO_FORMAT_A1,
                                                      mTransparencyBitmapWidth,
                                                      mTransparencyBitmapHeight,
                                                      GetBitmapStride(mTransparencyBitmapWidth));
     if (!maskBitmap)
         return;
 
     cairo_region_t * maskRegion = gdk_cairo_region_create_from_surface(maskBitmap);
     gtk_widget_shape_combine_region(mShell, maskRegion);
     cairo_region_destroy(maskRegion);
     cairo_surface_destroy(maskBitmap);
-#endif // MOZ_WIDGET_GTK == 2
 #endif // MOZ_X11
 }
 
 void
 nsWindow::ClearTransparencyBitmap()
 {
     if (!mTransparencyBitmap)
         return;
@@ -5283,22 +5168,18 @@ is_mouse_in_window (GdkWindow* aWindow, 
             break;
         }
 
         offsetX += tmpX;
         offsetY += tmpY;
         window = gdk_window_get_parent(window);
     }
 
-#if (MOZ_WIDGET_GTK == 2)
-    gdk_drawable_get_size(aWindow, &w, &h);
-#else
     w = gdk_window_get_width(aWindow);
     h = gdk_window_get_height(aWindow);
-#endif
 
     if (aMouseX > x && aMouseX < x + w &&
         aMouseY > y && aMouseY < y + h)
         return true;
 
     return false;
 }
 
@@ -5544,28 +5425,16 @@ get_gtk_cursor(nsCursor aCursor)
 
     gCursorCache[aCursor] = gdkcursor;
 
     return gdkcursor;
 }
 
 // gtk callbacks
 
-#if (MOZ_WIDGET_GTK == 2)
-static gboolean
-expose_event_cb(GtkWidget *widget, GdkEventExpose *event)
-{
-    RefPtr<nsWindow> window = get_window_for_gdk_window(event->window);
-    if (!window)
-        return FALSE;
-
-    window->OnExposeEvent(event);
-    return FALSE;
-}
-#else
 void
 draw_window_of_widget(GtkWidget *widget, GdkWindow *aWindow, cairo_t *cr)
 {
     if (gtk_cairo_should_draw_window(cr, aWindow)) {
         RefPtr<nsWindow> window = get_window_for_gdk_window(aWindow);
         if (!window) {
             NS_WARNING("Cannot get nsWindow from GtkWidget");
         }
@@ -5607,17 +5476,16 @@ expose_event_cb(GtkWidget *widget, cairo
         [](gpointer data) -> gboolean {
             g_object_unref(data);
             return G_SOURCE_REMOVE;
         },
         widget);
 
     return FALSE;
 }
-#endif //MOZ_WIDGET_GTK == 2
 
 static gboolean
 configure_event_cb(GtkWidget *widget,
                    GdkEventConfigure *event)
 {
     RefPtr<nsWindow> window = get_window_for_gtk_widget(widget);
     if (!window)
         return FALSE;
@@ -6218,21 +6086,17 @@ get_inner_gdk_window (GdkWindow *aWindow
 {
     gint cx, cy, cw, ch;
     GList *children = gdk_window_peek_children(aWindow);
     for (GList *child = g_list_last(children);
          child;
          child = g_list_previous(child)) {
         auto *childWindow = (GdkWindow *) child->data;
         if (get_window_for_gdk_window(childWindow)) {
-#if (MOZ_WIDGET_GTK == 2)
-            gdk_window_get_geometry(childWindow, &cx, &cy, &cw, &ch, nullptr);
-#else
             gdk_window_get_geometry(childWindow, &cx, &cy, &cw, &ch);
-#endif
             if ((cx < x) && (x < (cx + cw)) &&
                 (cy < y) && (y < (cy + ch)) &&
                 gdk_window_is_visible(childWindow)) {
                 return get_inner_gdk_window(childWindow,
                                             x - cx, y - cy,
                                             retx, rety);
             }
         }
@@ -6430,63 +6294,16 @@ nsWindow::GetEditCommands(NativeKeyBindi
             return;
         }
     }
 
     NativeKeyBindings* keyBindings = NativeKeyBindings::GetInstance(aType);
     keyBindings->GetEditCommands(aEvent, aCommands);
 }
 
-#if defined(MOZ_X11) && (MOZ_WIDGET_GTK == 2)
-/* static */ already_AddRefed<DrawTarget>
-nsWindow::GetDrawTargetForGdkDrawable(GdkDrawable* aDrawable,
-                                      const IntSize& aSize)
-{
-    GdkVisual* visual = gdk_drawable_get_visual(aDrawable);
-    Screen* xScreen =
-        gdk_x11_screen_get_xscreen(gdk_drawable_get_screen(aDrawable));
-    Display* xDisplay = DisplayOfScreen(xScreen);
-    Drawable xDrawable = gdk_x11_drawable_get_xid(aDrawable);
-
-    RefPtr<gfxASurface> surface;
-
-    if (visual) {
-        Visual* xVisual = gdk_x11_visual_get_xvisual(visual);
-
-        surface = new gfxXlibSurface(xDisplay, xDrawable, xVisual, aSize);
-    } else {
-        // no visual? we must be using an xrender format.  Find a format
-        // for this depth.
-        XRenderPictFormat *pf = nullptr;
-        switch (gdk_drawable_get_depth(aDrawable)) {
-            case 32:
-                pf = XRenderFindStandardFormat(xDisplay, PictStandardARGB32);
-                break;
-            case 24:
-                pf = XRenderFindStandardFormat(xDisplay, PictStandardRGB24);
-                break;
-            default:
-                NS_ERROR("Don't know how to handle the given depth!");
-                break;
-        }
-
-        surface = new gfxXlibSurface(xScreen, xDrawable, pf, aSize);
-    }
-
-    RefPtr<DrawTarget> dt =
-        gfxPlatform::GetPlatform()->CreateDrawTargetForSurface(surface, aSize);
-
-    if (!dt || !dt->IsValid()) {
-        return nullptr;
-    }
-
-    return dt.forget();
-}
-#endif
-
 already_AddRefed<DrawTarget>
 nsWindow::StartRemoteDrawingInRegion(LayoutDeviceIntRegion& aInvalidRegion, BufferMode* aBufferMode)
 {
   return mSurfaceProvider.StartRemoteDrawingInRegion(aInvalidRegion, aBufferMode);
 }
 
 void
 nsWindow::EndRemoteDrawingInRegion(DrawTarget* aDrawTarget,
--- a/widget/gtk/nsWindow.h
+++ b/widget/gtk/nsWindow.h
@@ -170,21 +170,17 @@ public:
 
     // utility method, -1 if no change should be made, otherwise returns a
     // value that can be passed to gdk_window_set_decorations
     gint               ConvertBorderStyles(nsBorderStyle aStyle);
 
     GdkRectangle DevicePixelsToGdkRectRoundOut(LayoutDeviceIntRect aRect);
 
     // event callbacks
-#if (MOZ_WIDGET_GTK == 2)
-    gboolean           OnExposeEvent(GdkEventExpose *aEvent);
-#else
     gboolean           OnExposeEvent(cairo_t *cr);
-#endif
     gboolean           OnConfigureEvent(GtkWidget *aWidget,
                                         GdkEventConfigure *aEvent);
     void               OnContainerUnrealize();
     void               OnSizeAllocate(GtkAllocation *aAllocation);
     void               OnDeleteEvent();
     void               OnEnterNotifyEvent(GdkEventCrossing *aEvent);
     void               OnLeaveNotifyEvent(GdkEventCrossing *aEvent);
     void               OnMotionNotifyEvent(GdkEventMotion *aEvent);
@@ -313,20 +309,16 @@ public:
    virtual nsTransparencyMode GetTransparencyMode() override;
 #if (MOZ_WIDGET_GTK >= 3)
    virtual void        UpdateOpaqueRegion(const LayoutDeviceIntRegion& aOpaqueRegion) override;
 #endif
    virtual nsresult    ConfigureChildren(const nsTArray<Configuration>& aConfigurations) override;
    nsresult            UpdateTranslucentWindowAlphaInternal(const nsIntRect& aRect,
                                                             uint8_t* aAlphas, int32_t aStride);
 
-#if (MOZ_WIDGET_GTK == 2)
-    static already_AddRefed<DrawTarget> GetDrawTargetForGdkDrawable(GdkDrawable* aDrawable,
-                                                                    const mozilla::gfx::IntSize& aSize);
-#endif
     virtual void       ReparentNativeWidget(nsIWidget* aNewParent) override;
 
     virtual nsresult SynthesizeNativeMouseEvent(LayoutDeviceIntPoint aPoint,
                                                 uint32_t aNativeMessage,
                                                 uint32_t aModifierFlags,
                                                 nsIObserver* aObserver) override;
 
     virtual nsresult SynthesizeNativeMouseMove(LayoutDeviceIntPoint aPoint,
--- a/xpcom/base/nsSystemInfo.cpp
+++ b/xpcom/base/nsSystemInfo.cpp
@@ -710,27 +710,16 @@ nsSystemInfo::Init()
 
 #if defined(MOZ_WIDGET_GTK)
   // This must be done here because NSPR can only separate OS's when compiled, not libraries.
   // 64 bytes is going to be well enough for "GTK " followed by 3 integers
   // separated with dots.
   char gtkver[64];
   ssize_t gtkver_len = 0;
 
-#if MOZ_WIDGET_GTK == 2
-  extern int gtk_read_end_of_the_pipe;
-
-  if (gtk_read_end_of_the_pipe != -1) {
-    do {
-      gtkver_len = read(gtk_read_end_of_the_pipe, &gtkver, sizeof(gtkver));
-    } while (gtkver_len < 0 && errno == EINTR);
-    close(gtk_read_end_of_the_pipe);
-  }
-#endif
-
   if (gtkver_len <= 0) {
     gtkver_len = SprintfLiteral(gtkver, "GTK %u.%u.%u", gtk_major_version,
                                 gtk_minor_version, gtk_micro_version);
   }
 
   nsAutoCString secondaryLibrary;
   if (gtkver_len > 0 && gtkver_len < int(sizeof(gtkver))) {
     secondaryLibrary.Append(nsDependentCSubstring(gtkver, gtkver_len));
--- a/xpcom/build/nsXULAppAPI.h
+++ b/xpcom/build/nsXULAppAPI.h
@@ -507,22 +507,16 @@ XRE_API(void,
 
 XRE_API(void,
         XRE_EnableSameExecutableForContentProc, ())
 
 XRE_API(int,
         XRE_XPCShellMain, (int argc, char** argv, char** envp,
                            const XREShellData* aShellData))
 
-#if MOZ_WIDGET_GTK == 2
-XRE_API(void,
-        XRE_GlibInit, ())
-#endif
-
-
 #ifdef LIBFUZZER
 #include "LibFuzzerRegistry.h"
 
 XRE_API(void,
         XRE_LibFuzzerSetDriver, (LibFuzzerDriver))
 
 #endif // LIBFUZZER
 
--- a/xpcom/glue/standalone/nsXPCOMGlue.cpp
+++ b/xpcom/glue/standalone/nsXPCOMGlue.cpp
@@ -358,25 +358,16 @@ public:
       // initializers, so this needs to happen before glib is loaded, which is
       // this is hooked in XPCOMGlueStartup before libxul is loaded. This
       // relies on the main executable not depending on glib.
       setenv("G_SLICE", "always-malloc", 1);
     }
   }
 
   ~GSliceInit() {
-#if MOZ_WIDGET_GTK == 2
-    if (sTop) {
-      auto XRE_GlibInit = (void (*)(void)) GetSymbol(sTop->libHandle,
-        "XRE_GlibInit");
-      // Initialize glib enough for G_SLICE to have an effect before it is unset.
-      // unset.
-      XRE_GlibInit();
-    }
-#endif
     if (!mHadGSlice) {
       unsetenv("G_SLICE");
     }
   }
 
 private:
   bool mHadGSlice;
 };