Re-add snap-back behavior (Chrome side)

content/renderer/renderer_webkitplatformsupport_impl.h

Index: content/renderer/renderer_webkitplatformsupport_impl.h
===================================================================
--- content/renderer/renderer_webkitplatformsupport_impl.h	(revision 252686)
+++ content/renderer/renderer_webkitplatformsupport_impl.h	(working copy)
@@ -43,6 +43,7 @@
 class WebCryptoImpl;
 class WebDatabaseObserverImpl;
 class WebFileSystemImpl;
+class WebScrollbarBehaviorImpl;
 
 class CONTENT_EXPORT RendererWebKitPlatformSupportImpl
     : public WebKitPlatformSupportImpl {
@@ -91,6 +92,7 @@
                              blink::WebPluginListBuilder* builder);
   virtual blink::WebPublicSuffixList* publicSuffixList();
   virtual void screenColorProfile(blink::WebVector<char>* to_profile);
+  virtual blink::WebScrollbarBehavior* scrollbarBehavior();
   virtual blink::WebIDBFactory* idbFactory();
   virtual blink::WebFileSystem* fileSystem();
   virtual bool canAccelerate2dCanvas();
@@ -218,6 +220,8 @@
 
   scoped_ptr<WebCryptoImpl> web_crypto_;
 
+  scoped_ptr<WebScrollbarBehaviorImpl> web_scrollbar_behavior_;
+
   DISALLOW_COPY_AND_ASSIGN(RendererWebKitPlatformSupportImpl);
 };