Fixed clip resize for document.rootScroller with inertTopControls

third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp

Index: third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
diff --git a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
index 5d6d6d3fb280d241804e343a125a07cfdbfc5af3..bb4678bd4c97637523f0ed2c4364401b3b39f0df 100644
--- a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
+++ b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.cpp
@@ -41,6 +41,26 @@ void TopDocumentRootScrollerController::didChangeRootScroller() {
   recomputeGlobalRootScroller();
 }
 
+void TopDocumentRootScrollerController::mainFrameViewResized() {
+  Element* rootScroller = globalRootScroller();
+  if (!rootScroller)
+    return;
+
+  ScrollableArea* area = RootScrollerUtil::scrollableAreaFor(*rootScroller);
+
+  if (!area)
+    return;
+
+  if (PaintLayer* layer = area->layer()) {
+    layer->setNeedsCompositingInputsUpdate();
+
+    // This is needed if the root scroller is an iframe, since the iframe
+    // doesn't have a scrolling/clip layer, its PLC has a container layer that
+    // needs to be resized instead.
+    layer->compositor()->frameViewDidChangeSize();
+  }
+}
+
 Element* TopDocumentRootScrollerController::findGlobalRootScrollerElement() {
   if (!topDocument())
     return nullptr;
@@ -179,6 +199,10 @@ GraphicsLayer* TopDocumentRootScrollerController::rootScrollerLayer() const {
   return graphicsLayer;
 }
 
+PaintLayer* TopDocumentRootScrollerController::rootScrollerPaintLayer() const {
+  return RootScrollerUtil::paintLayerFor(m_globalRootScroller);
+}
+
 Element* TopDocumentRootScrollerController::globalRootScroller() const {
   return m_globalRootScroller.get();
 }