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

content/browser/android/content_view_core_impl.h

 // Copyright 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_BROWSER_ANDROID_CONTENT_VIEW_CORE_IMPL_H_
 #define CONTENT_BROWSER_ANDROID_CONTENT_VIEW_CORE_IMPL_H_
 
 #include <vector>
 
 #include "base/android/jni_android.h"
@@ skipping 334 matching lines @@
   blink::WebGestureEvent MakeGestureEvent(
       blink::WebInputEvent::Type type, int64 time_ms, float x, float y) const;
 
   void SendBeginFrame(base::TimeTicks frame_time);
 
   gfx::Size GetViewportSizePix() const;
   gfx::Size GetViewportSizeOffsetPix() const;
 
   void DeleteScaledSnapshotTexture();
 
+  bool OnMotionEvent(const ui::MotionEvent& event);

[tdresser, 2014/03/28 17:55:27]

Would DispatchMotionEvent be a better name?

[jdduke (slow), 2014/03/28 18:33:55]

Probably, but in the Java boundary land |OnFoo| is essentially equivalent to
|DispatchFoo| and I'm not sure there's a need to clarify.

[tdresser, 2014/03/28 18:40:05]

Fine with me.

   void SendGestureEvent(const blink::WebGestureEvent& event);
 
   // Update focus state of the RenderWidgetHostView.
   void SetFocusInternal(bool focused);
 
   // Send device_orientation_ to renderer.
   void SendOrientationChangeEventInternal();
 
   // Utility method for synthesizing a touch cancel event and dispatching it
   // through the touch pipeline.
@@ skipping 38 matching lines @@
   bool geolocation_needs_pause_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentViewCoreImpl);
 };
 
 bool RegisterContentViewCore(JNIEnv* env);
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_ANDROID_CONTENT_VIEW_CORE_IMPL_H_