Bug 1721707 [Wayland] Build fix for X11 only environment r=emilio

Differential Revision: https://phabricator.services.mozilla.com/D121460

widget/gtk/ScreenHelperGTK.cpp

@@ -197,6 +197,7 @@ void ScreenGetterGtk::RefreshScreens() {
   screenManager.Refresh(std::move(screenList));
 }
 
+#ifdef MOZ_WAYLAND
 static void output_handle_geometry(void* data, struct wl_output* wl_output,
                                    int x, int y, int physical_width,
                                    int physical_height, int subpixel,
@@ -410,6 +411,7 @@ void ScreenGetterWayland::GetScreenRectForWindow(nsWindow* aWindow,
   aRect->width = mMonitors[monitor].width;
   aRect->height = mMonitors[monitor].height;
 }
+#endif
 
 RefPtr<nsIScreen> ScreenHelperGTK::GetScreenForWindow(nsWindow* aWindow) {
   return gScreenGetter->GetScreenForWindow(aWindow);
@@ -426,9 +428,12 @@ gint ScreenHelperGTK::GetGTKMonitorScaleFactor(gint aMonitorNum) {
 }
 
 ScreenHelperGTK::ScreenHelperGTK() {
+#ifdef MOZ_WAYLAND
   if (GdkIsWaylandDisplay()) {
     gScreenGetter = mozilla::MakeUnique<ScreenGetterWayland>();
-  } else {
+  }
+#endif
+  if (!gScreenGetter) {
     gScreenGetter = mozilla::MakeUnique<ScreenGetterGtk>();
   }
   gScreenGetter->Init();

widget/gtk/ScreenHelperGTK.h

@@ -71,6 +71,7 @@ struct MonitorConfig {
   explicit MonitorConfig(int aId) : id(aId){};
 };
 
+#ifdef MOZ_WAYLAND
 class ScreenGetterWayland : public ScreenGetter {
  public:
   ScreenGetterWayland() : mRegistry() {};
@@ -96,6 +97,7 @@ class ScreenGetterWayland : public ScreenGetter {
   AutoTArray<MonitorConfig, 4> mMonitors;
   AutoTArray<RefPtr<Screen>, 4> mScreenList;
 };
+#endif
 
 class ScreenHelperGTK final : public ScreenManager::Helper {
  public:

widget/gtk/nsDragService.h

@@ -14,7 +14,12 @@
 
 class nsICookieJarSettings;
 class nsWindow;
+
+#ifdef MOZ_WAYLAND
 class DataOffer;
+#else
+typedef nsISupports DataOffer;
+#endif
 
 namespace mozilla {
 namespace gfx {