setNeedsPaintPropertyUpdate on FrameView contents size change

third_party/WebKit/Source/core/frame/FrameView.cpp

Index: third_party/WebKit/Source/core/frame/FrameView.cpp
diff --git a/third_party/WebKit/Source/core/frame/FrameView.cpp b/third_party/WebKit/Source/core/frame/FrameView.cpp
index 1af62f777d806aee66e8d8e0f2d162ce87fb8266..66f377675817bd498412d0f567f5a610a9440509 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.cpp
+++ b/third_party/WebKit/Source/core/frame/FrameView.cpp
@@ -636,6 +636,10 @@ void FrameView::setContentsSize(const IntSize& size) {
   updateScrollbars();
   ScrollableArea::contentsResized();
 
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() &&
+      !RuntimeEnabledFeatures::rootLayerScrollingEnabled())
+    setNeedsPaintPropertyUpdate();
+
   Page* page = frame().page();
   if (!page)
     return;