Move middle-click autoscroll to synthetic fling.

third_party/WebKit/Source/web/ChromeClientImpl.h

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 153 matching lines @@
   void UpdateCompositedSelection(LocalFrame*,
                                  const CompositedSelection&) override;
 
   // ChromeClient methods:
   String AcceptLanguages() override;
   void SetCursorForPlugin(const WebCursorInfo&, LocalFrame*) override;
 
   // ChromeClientImpl:
   void SetNewWindowNavigationPolicy(WebNavigationPolicy);
 
+  void AutoscrollStart(WebFloatPoint viewport_point, LocalFrame*) override;
+  void AutoscrollFling(WebFloatSize velocity, LocalFrame*) override;
+  void AutoscrollEnd(LocalFrame*) override;
+
   bool HasOpenedPopup() const override;
   PopupMenu* OpenPopupMenu(LocalFrame&, HTMLSelectElement&) override;
   PagePopup* OpenPagePopup(PagePopupClient*) override;
   void ClosePagePopup(PagePopup*) override;
   DOMWindow* PagePopupWindowForTesting() const override;
 
   bool ShouldOpenModalDialogDuringPageDismissal(
       LocalFrame&,
       DialogType,
       const String& dialog_message,
@@ skipping 65 matching lines @@
 
 DEFINE_TYPE_CASTS(ChromeClientImpl,
                   ChromeClient,
                   client,
                   client->IsChromeClientImpl(),
                   client.IsChromeClientImpl());
 
 }  // namespace blink
 
 #endif