[Android] Short-circuit touch forwarding when no touch handlers exist

content/browser/renderer_host/input/web_input_event_builders_android.h

 // Copyright 2013 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_BROWSER_RENDERER_HOST_INPUT_WEB_INPUT_EVENT_BUILDERS_ANDROID_H_
 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_WEB_INPUT_EVENT_BUILDERS_ANDROID_H_
 
 #include <jni.h>
 
 #include "third_party/WebKit/public/web/WebInputEvent.h"
@@ skipping 39 matching lines @@
 };
 
 class WebGestureEventBuilder {
  public:
   static blink::WebGestureEvent Build(blink::WebInputEvent::Type type,
                                       double time_sec,
                                       int x,
                                       int y);
 };
 
-class WebTouchEventBuilder {
- public:
-  static blink::WebTouchEvent Build(const MotionEventAndroid& event,
-                                    float scale);
-};
-
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_WEB_INPUT_EVENT_BUILDERS_ANDROID_H_