Bug 1546374 - Do not adjust position of popup windows on Wayland; r=stransky

Because adjusting position in the Wayland does not work
(because of unknown absolute position of the window), do not try
to adjust popup position under Wayland.

Differential Revision: https://phabricator.services.mozilla.com/D28480

--HG--
extra : moz-landing-system : lando

layout/xul/moz.build

@@ -74,6 +74,9 @@ if CONFIG['MOZ_XUL']:
 if CONFIG['MOZ_XUL']:
     DIRS += ['tree', 'grid']
 
+CFLAGS += CONFIG['TK_CFLAGS']
+CXXFLAGS += CONFIG['TK_CFLAGS']
+
 include('/ipc/chromium/chromium-config.mozbuild')
 
 FINAL_LIBRARY = 'xul'

layout/xul/nsMenuPopupFrame.cpp

@@ -56,6 +56,11 @@
 #include "mozilla/dom/KeyboardEvent.h"
 #include "mozilla/dom/KeyboardEventBinding.h"
 #include <algorithm>
+#ifdef MOZ_WAYLAND
+#  include <gdk/gdk.h>
+#  include <gdk/gdkx.h>
+#  include <gdk/gdkwayland.h>
+#endif /* MOZ_WAYLAND */
 
 using namespace mozilla;
 using mozilla::dom::Document;
@@ -1494,14 +1499,20 @@ nsresult nsMenuPopupFrame::SetPopupPosition(nsIFrame* aAnchorFrame,
 
   nscoord oldAlignmentOffset = mAlignmentOffset;
 
+  bool inWayland = false;
+#ifdef MOZ_WAYLAND
+  inWayland = !GDK_IS_X11_DISPLAY(gdk_display_get_default());
+#endif
+
   // If a panel is being moved or has flip="none", don't constrain or flip it,
   // in order to avoid visual noise when moving windows between screens.
   // However, if a panel is already constrained or flipped (mIsOffset), then we
   // want to continue to calculate this. Also, always do this for content
   // shells, so that the popup doesn't extend outside the containing frame.
-  if (mInContentShell ||
+  if (!inWayland &&
+      (mInContentShell ||
        (mFlip != FlipType_None &&
-       (!aIsMove || mIsOffset || mPopupType != ePopupTypePanel))) {
+        (!aIsMove || mIsOffset || mPopupType != ePopupTypePanel)))) {
     int32_t appPerDev = presContext->AppUnitsPerDevPixel();
     LayoutDeviceIntRect anchorRectDevPix =
         LayoutDeviceIntRect::FromAppUnitsToNearest(anchorRect, appPerDev);