MainFrame scrollbars should work with RFV instead of FV

third_party/WebKit/Source/core/frame/VisualViewport.cpp

Index: third_party/WebKit/Source/core/frame/VisualViewport.cpp
diff --git a/third_party/WebKit/Source/core/frame/VisualViewport.cpp b/third_party/WebKit/Source/core/frame/VisualViewport.cpp
index b3d9289919704cda8b0bba084442d9d350be34f9..c89d7d9cfa086bec8d4cb27fd3b6b4319c6515f2 100644
--- a/third_party/WebKit/Source/core/frame/VisualViewport.cpp
+++ b/third_party/WebKit/Source/core/frame/VisualViewport.cpp
@@ -296,6 +296,8 @@ bool VisualViewport::didSetScaleOrLocation(float scale,
 
   clampToBoundaries();
 
+  mainFrame()->view()->updateScrollbars();

[bokan, 2016/10/31 15:25:09]

VisualViewport shouldn't be talking to FrameView, this should happen though the
RFV. There's already VisualViewport::notifyRootFrameViewport, just call into
FrameView::updateScrollbars from RootFrameViewport::didUpdateVisualViewport

[ymalik, 2016/11/03 18:49:12]

Yes you're right.

I have RFV::didUpdateVisualViewport calling updateScrollbars now.

+
   return true;
 }