File 2.diff of Package Firefox

diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
--- a/widget/gtk/nsWindow.cpp
+++ b/widget/gtk/nsWindow.cpp
@@ -1993,22 +1993,28 @@ void nsWindow::NativeMoveResizeWaylandPo
     // from layout.
     NativeMoveResize(movedByLayout, resizedByLayout);
     return;
   }
 
   LOG("  orig mBounds [%d, %d] -> [%d x %d]\n", mBounds.x, mBounds.y,
       mBounds.width, mBounds.height);
 
-  LayoutDeviceIntRect newBounds = [&] {
+  const LayoutDeviceIntRect newBounds = [&] {
     GdkRectangle finalRect = *aFinalSize;
     GdkPoint parent = WaylandGetParentPosition();
     finalRect.x += parent.x;
     finalRect.y += parent.y;
-    return GdkRectToDevicePixels(finalRect);
+    auto roundTo = RoundsWidgetCoordinatesTo();
+    auto rect = GdkRectToDevicePixels(finalRect);
+    // Ensure we do the same rounding that nsView would do, see
+    // MaybeRoundToDisplayPixels.
+    auto size = !mIsTransparent ? rect.Size().TruncatedToMultiple(roundTo)
+                                : rect.Size().CeiledToMultiple(roundTo);
+    return LayoutDeviceIntRect(rect.TopLeft().RoundedToMultiple(roundTo), size);
   }();
 
   LOG("  new mBounds [%d, %d] -> [%d x %d]", newBounds.x, newBounds.y,
       newBounds.width, newBounds.height);
 
   bool needsPositionUpdate = newBounds.TopLeft() != mBounds.TopLeft();
   bool needsSizeUpdate = newBounds.Size() != mLastSizeRequest;