Fixed clip resize for document.rootScroller with inertTopControls

third_party/WebKit/Source/platform/scroll/ScrollableArea.h

Index: third_party/WebKit/Source/platform/scroll/ScrollableArea.h
diff --git a/third_party/WebKit/Source/platform/scroll/ScrollableArea.h b/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
index eb2188d991bef84d430ee3ae6369dca28dc90d9a..2c20b6ea2cec866b90a4dd9a595f2243a7a740cb 100644
--- a/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
+++ b/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
@@ -45,6 +45,7 @@ class GraphicsLayer;
 class HostWindow;
 class LayoutBox;
 class LayoutObject;
+class PaintLayer;
 class ProgrammaticScrollAnimator;
 struct ScrollAlignment;
 class ScrollAnchor;
@@ -200,6 +201,8 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
   virtual Scrollbar* horizontalScrollbar() const { return nullptr; }
   virtual Scrollbar* verticalScrollbar() const { return nullptr; }
 
+  virtual PaintLayer* layer() const { return nullptr; }
+
   // scrollPosition is the location of the top/left of the scroll viewport in
   // the coordinate system defined by the top/left of the overflow rect.
   // scrollOffset is the offset of the scroll viewport from its position when