Add a bit to not bubble scrolls to parent scrolling layers

cc/input_handler.h

 // Copyright 2011 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 CC_INPUT_HANDLER_H_
 #define CC_INPUT_HANDLER_H_
 
 #include "base/basictypes.h"
 #include "base/time.h"
 #include "cc/cc_export.h"
@@ skipping 10 matching lines @@
 // the impl thread side of the compositor implementation.
 //
 // There is one InputHandler for every LayerTreeHost. It is
 // created on the main thread and used only on the impl thread.
 //
 // The InputHandler is constructed with a InputHandlerClient, which is the
 // interface by which the handler can manipulate the LayerTree.
 class CC_EXPORT InputHandlerClient {
 public:
     enum ScrollStatus { ScrollOnMainThread, ScrollStarted, ScrollIgnored };
-    enum ScrollInputType { Gesture, Wheel };
+    enum ScrollInputType { Gesture, Wheel, NonBubblingGesture };
 
     // Selects a layer to be scrolled at a given point in viewport (logical
     // pixel) coordinates. Returns ScrollStarted if the layer at the coordinates
     // can be scrolled, ScrollOnMainThread if the scroll event should instead be
     // delegated to the main thread, or ScrollIgnored if there is nothing to be
     // scrolled at the given coordinates.
     virtual ScrollStatus scrollBegin(gfx::Point, ScrollInputType) = 0;
 
     // Scroll the selected layer starting at the given position. If the scroll
     // type given to scrollBegin was a gesture, then the scroll point and delta
@@ skipping 44 matching lines @@
 protected:
     InputHandler() { }
 
 private:
     DISALLOW_COPY_AND_ASSIGN(InputHandler);
 };
 
 }
 
 #endif  // CC_INPUT_HANDLER_H_