Revert "MainFrame scrollbars should work with RFV instead of FV"

third_party/WebKit/Source/core/frame/RootFrameViewport.h

Index: third_party/WebKit/Source/core/frame/RootFrameViewport.h
diff --git a/third_party/WebKit/Source/core/frame/RootFrameViewport.h b/third_party/WebKit/Source/core/frame/RootFrameViewport.h
index 729ec726bc016c5af7b027c561179b98d23c88c7..93e554d80a95318c2f1f04990b88476a668d2843 100644
--- a/third_party/WebKit/Source/core/frame/RootFrameViewport.h
+++ b/third_party/WebKit/Source/core/frame/RootFrameViewport.h
@@ -64,6 +64,11 @@ class CORE_EXPORT RootFrameViewport final
   IntRect visibleContentRect(
       IncludeScrollbarsInRect = ExcludeScrollbars) const override;
   bool shouldUseIntegerScrollOffset() const override;
+  LayoutRect visualRectForScrollbarParts() const override {
+    ASSERT_NOT_REACHED();
+    return LayoutRect();
+  }
+  bool isActive() const override;
   int scrollSize(ScrollbarOrientation) const override;
   bool isScrollCornerVisible() const override;
   IntRect scrollCornerRect() const override;
@@ -102,34 +107,6 @@ class CORE_EXPORT RootFrameViewport final
                                       const LayoutObject*,
                                       unsigned = 0) const final;
 
-  // Scrollbar related
-  // TODO(crbug.com/661236): Seperate the scrollbar related logic from
-  // ScrollableArea.
-  Scrollbar* horizontalScrollbar() const override;
-  Scrollbar* verticalScrollbar() const override;
-  bool isActive() const override;
-  bool hasOverlayScrollbars() const override;
-  void setScrollbarNeedsPaintInvalidation(ScrollbarOrientation) override;
-  LayoutRect visualRectForScrollbarParts() const override;
-  ScrollbarOverlayColorTheme getScrollbarOverlayColorTheme() const override;
-  void getTickmarks(Vector<IntRect>& rects) const override;
-  void mouseEnteredScrollbar(Scrollbar&) override;
-  void mouseExitedScrollbar(Scrollbar&) override;
-  void scrollbarVisibilityChanged() override;
-  bool scrollbarsHidden() const override;
-  IntRect convertFromScrollbarToContainingWidget(const Scrollbar&,
-                                                 const IntRect&) const override;
-  IntRect convertFromContainingWidgetToScrollbar(const Scrollbar&,
-                                                 const IntRect&) const override;
-  IntPoint convertFromScrollbarToContainingWidget(
-      const Scrollbar&,
-      const IntPoint&) const override;
-  IntPoint convertFromContainingWidgetToScrollbar(
-      const Scrollbar&,
-      const IntPoint&) const override;
-  ScrollOffset scrollAnimatorDesiredTargetOffset() const override;
-  void setScrollCornerNeedsPaintInvalidation() override;
-
  private:
   RootFrameViewport(ScrollableArea& visualViewport,
                     ScrollableArea& layoutViewport);