Forward mouse down node information to WebWidgetClient

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 147 matching lines @@
     // coordinates.
     // |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 when there is mouse press or gesture tap event.
+    virtual void onClickInput(const WebNode& clickedNode) { }

[Rick Byers, 2015/06/18 17:02:10]

You've implemented this to be at mousedown time (and the node is the one that
received the mosuedown event) which isn't the same as "click" (or
"clickedNode").  Is that the behavior to want to match PageClickTracker?  If so,
please rename this to something like onMouseDown with a comment like: "Called
immediately after a mousedown event is dispatched due to a mouse press or
gesture tap event".

[Yufeng Shen (Slow to review), 2015/06/18 18:29:04]

Done.

 protected:
     ~WebWidgetClient() { }
 };
 
 } // namespace blink
 
 #endif