mac: History swiping doesn't work right with iframes.

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>
 
 // 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.
 // The delegator object will call the -viewGone: method when it is going away.
 
 @class NSEvent;
 @protocol RenderWidgetHostViewMacDelegate
 @optional
 // Notification that the view is gone.
 - (void)viewGone:(NSView*)view;
 
 // Handle an event. All incoming key and mouse events flow through this delegate
 // method if implemented. Return YES if the event is fully handled, or NO if
 // normal processing should take place.
 - (BOOL)handleEvent:(NSEvent*)event;
 
-// Notification that a wheel event was unhandled.
-- (void)gotUnhandledWheelEvent;
-
-// Notification of scroll offset pinning.
-- (void)scrollOffsetPinnedToLeft:(BOOL)left toRight:(BOOL)right;
-
-// Notification of whether the view has a horizontal scrollbar.
-- (void)setHasHorizontalScrollbar:(BOOL)has_horizontal_scrollbar;
-
 // Provides validation of user interface items. If the return value is NO, then
 // the delegate is unaware of that item and |valid| is undefined.  Otherwise,
 // |valid| contains the validity of the specified item.
 - (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)item
                       isValidItem:(BOOL*)valid;
 
 @required
 // Notification of when a gesture begins/ends.
 - (void)beginGestureWithEvent:(NSEvent*)event;
 - (void)endGestureWithEvent:(NSEvent*)event;
 
 // This is a low level API which provides touches associated with an event.
 // It is used in conjunction with gestures to determine finger placement
 // on the trackpad.
 - (void)touchesMovedWithEvent:(NSEvent*)event;
 - (void)touchesBeganWithEvent:(NSEvent*)event;
 - (void)touchesCancelledWithEvent:(NSEvent*)event;
 - (void)touchesEndedWithEvent:(NSEvent*)event;
 
 // 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;
+
+// Notification that a wheel event was received.
+// |consumed| indicates whether the renderer or the render_widget_host_view
+// delegate consumed the event.
+- (void)gotWheelEventConsumed:(BOOL)consumed;
 @end
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_MAC_DELEGATE_H_