MainFrame scrollbars should work with RFV instead of FV

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..930a1ceab8ed0256359307d84c37f410e7066ac4 100644
--- a/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
+++ b/third_party/WebKit/Source/platform/scroll/ScrollableArea.h
@@ -109,10 +109,11 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
   void mouseEnteredContentArea() const;
   void mouseExitedContentArea() const;
   void mouseMovedInContentArea() const;
-  void mouseEnteredScrollbar(Scrollbar&);
-  void mouseExitedScrollbar(Scrollbar&);
+  virtual void mouseEnteredScrollbar(Scrollbar&);
+  virtual void mouseExitedScrollbar(Scrollbar&);
   void mouseCapturedScrollbar();
   void mouseReleasedScrollbar();
+
   void contentAreaDidShow() const;
   void contentAreaDidHide() const;
 
@@ -123,10 +124,10 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
 
   virtual void contentsResized();
 
-  bool hasOverlayScrollbars() const;
+  virtual bool hasOverlayScrollbars() const;
   void setScrollbarOverlayColorTheme(ScrollbarOverlayColorTheme);
   void recalculateScrollbarOverlayColorTheme(Color);
-  ScrollbarOverlayColorTheme getScrollbarOverlayColorTheme() const {
+  virtual ScrollbarOverlayColorTheme getScrollbarOverlayColorTheme() const {
     return static_cast<ScrollbarOverlayColorTheme>(
         m_scrollbarOverlayColorTheme);
   }
@@ -167,10 +168,10 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
 
   virtual bool isActive() const = 0;
   virtual int scrollSize(ScrollbarOrientation) const = 0;
-  void setScrollbarNeedsPaintInvalidation(ScrollbarOrientation);
+  virtual void setScrollbarNeedsPaintInvalidation(ScrollbarOrientation);
   virtual bool isScrollCornerVisible() const = 0;
   virtual IntRect scrollCornerRect() const = 0;
-  void setScrollCornerNeedsPaintInvalidation();
+  virtual void setScrollCornerNeedsPaintInvalidation();
   virtual void getTickmarks(Vector<IntRect>&) const {}
 
   // Convert points and rects between the scrollbar and its containing Widget.
@@ -200,6 +201,12 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
   virtual Scrollbar* horizontalScrollbar() const { return nullptr; }
   virtual Scrollbar* verticalScrollbar() const { return nullptr; }
 
+  // TODO(crbug.com/661236): This method should be moved to ScrollbarManager
+  // which will update the scrollbars directly for all subclasses.
+  // Called to update the scrollbars to accurately reflect the state of the
+  // view.
+  virtual void updateScrollbars(){};
+
   // 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
@@ -221,6 +228,9 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
   virtual ScrollOffset maximumScrollOffset() const {
     return ScrollOffset(maximumScrollOffsetInt());
   }
+  virtual ScrollOffset scrollAnimatorDesiredTargetOffset() const {
+    return scrollAnimator().desiredTargetOffset();
+  }
 
   virtual IntRect visibleContentRect(
       IncludeScrollbarsInRect = ExcludeScrollbars) const;
@@ -231,6 +241,11 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
 
   virtual bool shouldSuspendScrollAnimations() const { return true; }
   virtual void scrollbarStyleChanged() {}
+  // Called when scrollbar hides/shows for overlay scrollbars. This callback
+  // shouldn't do any significant work as it can be called unexpectadly often
+  // on Mac. This happens because painting code has to set alpha to 1, paint,
+  // then reset to alpha, causing spurrious "visibilityChanged" calls.
+  virtual void scrollbarVisibilityChanged() {}
   virtual bool scrollbarsCanBeActive() const = 0;
 
   // Returns the bounding box of this scrollable area, in the coordinate system
@@ -392,12 +407,6 @@ class PLATFORM_EXPORT ScrollableArea : public GarbageCollectedMixin {
   }
   void showOverlayScrollbars();
 
-  // Called when scrollbar hides/shows for overlay scrollbars. This callback
-  // shouldn't do any significant work as it can be called unexpectadly often
-  // on Mac. This happens because painting code has to set alpha to 1, paint,
-  // then reset to alpha, causing spurrious "visibilityChanged" calls.
-  virtual void scrollbarVisibilityChanged() {}
-
  private:
   void programmaticScrollHelper(const ScrollOffset&, ScrollBehavior);
   void userScrollHelper(const ScrollOffset&, ScrollBehavior);