Fix page navigation being incorrectly fired on Mac OSX.

content/public/browser/render_widget_host_view_mac_delegate.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_RENDER_WIDGET_HOST_VIEW_MAC_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_MAC_DELEGATE_H_
 
 #import <Cocoa/Cocoa.h>
 
 namespace blink {
+class WebGestureEvent;
 class WebMouseWheelEvent;
 }
 
 // This protocol is used as a delegate for the NSView class used in the
 // hierarchy. There are two ways to extend the view:
 // - Implement the methods listed in the protocol below.
 // - Implement any method, and if the view is requested to perform that method
 //   and cannot, the delegate's implementation will be used.
 //
 // Like any Objective-C delegate, it is not retained by the delegator object.
@@ skipping 32 matching lines @@
 // These methods control whether a given view is allowed to rubberband in the
 // given direction. This is inversely related to whether the view is allowed to
 // 2-finger history swipe in the given direction.
 - (BOOL)canRubberbandLeft:(NSView*)view;
 - (BOOL)canRubberbandRight:(NSView*)view;
 
 // The browser process received an ACK from the renderer after it processed
 // |event|.
 - (void)rendererHandledWheelEvent:(const blink::WebMouseWheelEvent&)event
                          consumed:(BOOL)consumed;
+- (void)rendererHandledGestureScrollEvent:(const blink::WebGestureEvent&)event
+                                 consumed:(BOOL)consumed;
 @end
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_MAC_DELEGATE_H_