Make WebContentsObserver::DidGetUserInteraction fire on TouchStart instead of GestureTapBegin.

content/public/browser/web_contents_observer.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 #define CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_
 
 #include <stdint.h>
 
 #include "base/macros.h"
@@ skipping 335 matching lines @@
   // invokes this method. If there are ongoing navigations, their respective
   // failure methods will also be invoked.
   virtual void NavigationStopped() {}
 
   // Called when there has been direct user interaction with the WebContents.
   // The type argument specifies the kind of interaction. Direct user input
   // signalled through this callback includes:
   // 1) any mouse down event (blink::WebInputEvent::MouseDown);
   // 2) the start of a scroll (blink::WebInputEvent::GestureScrollBegin);
   // 3) any raw key down event (blink::WebInputEvent::RawKeyDown);
-  // 4) any gesture tap event (blink::WebInputEvent::GestureTapDown); and
+  // 4) any touch event (inc. scrolls) (blink::WebInputEvent::TouchStart); and
   // 5) a browser navigation or reload (blink::WebInputEvent::Undefined).
   virtual void DidGetUserInteraction(const blink::WebInputEvent::Type type) {}
 
   // This method is invoked when a RenderViewHost of this WebContents was
   // configured to ignore UI events, and an UI event took place.
   virtual void DidGetIgnoredUIEvent() {}
 
   // These methods are invoked every time the WebContents changes visibility.
   virtual void WasShown() {}
   virtual void WasHidden() {}
@@ skipping 147 matching lines @@
   void ResetWebContents();
 
   WebContentsImpl* web_contents_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentsObserver);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_WEB_CONTENTS_OBSERVER_H_