Expand PaintLayer clip to account for hidden URL bar with document.rootScroller

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

Index: third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.h
diff --git a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.h b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.h
index 58cc5e76d27aec242552e9c05f23a88df192714e..d51a7096f48e68a4574a96e2f1d259e45b72ce1f 100644
--- a/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.h
+++ b/third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.h
@@ -9,6 +9,7 @@
 #include "core/page/scrolling/RootScrollerController.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/heap/Handle.h"
+#include "platform/scroll/ScrollTypes.h"
 
 namespace blink {
 
@@ -74,8 +75,11 @@ class CORE_EXPORT TopDocumentRootScrollerController
   ScrollableArea* rootScrollerArea() const;
 
   // Returns the size we should use for the root scroller, accounting for top
-  // controls adjustment and using the root FrameView.
-  IntSize rootScrollerVisibleArea() const;
+  // controls adjustment and using the root FrameView rect.
+  IntRect visibleContentRect(IncludeScrollbarsInRect) const;
+
+  // Returns whether node is the root scroller or has it as a descendant.
+  bool isRootScrollerAncestor(const Node&) const;
 
  private:
   TopDocumentRootScrollerController(FrameHost&);