Move onMouseDown from WebWidgetClient to WebViewClient.

third_party/WebKit/public/web/WebWidgetClient.h

 /*
  * Copyright (C) 2009 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 142 matching lines @@
     // |tappedNode| is the node that the mouseDown event hit, provided so the
     // UI can be shown only on certain kinds of nodes in specific locations.
     // |pageChanged| is true if and only if the DOM tree or style was
     // modified during the dispatch of the mouse*, or click events associated
     // with the tap.
     // This provides a heuristic to help identify when a page is doing
     // something as a result of a tap without explicitly consuming the event.
     virtual void showUnhandledTapUIIfNeeded(const WebPoint& tappedPosition,
         const WebNode& tappedNode, bool pageChanged) { }
 
-    // Called immediately after a mousedown event is dispatched due to a mouse
-    // press or gesture tap.
-    // Note: This is called even when the mouse down event is prevent default.
-    virtual void onMouseDown(const WebNode& mouseDownNode) { }
-
     // Converts the |rect| from Blink's Viewport coordinates to the
     // coordinates in the native window used to display the content, in
     // DIP.  They're identical in tradional world, but will differ when
     // use-zoom-for-dsf feature is eanbled, and Viewport coordinates
     // becomes DSF times larger than window coordinates.
     // TODO(oshima): Update the comment when the migration is completed.
     virtual void convertViewportToWindow(WebRect* rect) {}
 
     // Converts the |rect| from the coordinates in native window in
     // DIP to Blink's Viewport coordinates. They're identical in
     // tradional world, but will differ when use-zoom-for-dsf feature
     // is eanbled.  TODO(oshima): Update the comment when the
     // migration is completed.
     virtual void convertWindowToViewport(WebFloatRect* rect) {}
 
 protected:
     ~WebWidgetClient() { }
 };
 
 } // namespace blink
 
 #endif