Remove GraphicsLayer::didScroll and directly call ScrollableArea::didScroll

third_party/WebKit/public/platform/WebLayerScrollClient.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 14 matching lines @@
 #ifndef WebLayerScrollClient_h
 #define WebLayerScrollClient_h
 
 #include "WebCommon.h"
 
 namespace blink {
 
 // A client that is notified of scrolling on a WebLayer.
 class BLINK_PLATFORM_EXPORT WebLayerScrollClient {
  public:
-  virtual void didScroll() = 0;
+  virtual void didScroll(const gfx::ScrollOffset&) = 0;
 
  protected:
   virtual ~WebLayerScrollClient() {}
 };
 
 }  // namespace blink
 
 #endif  // WebLayerScrollClient_h