events: Change gesture-event handler in EventHandler to not return any values.

ui/views/widget/native_widget_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 UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 #define UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_
 
 #include <vector>
 
 #include "ui/base/events/event_constants.h"
@@ skipping 94 matching lines @@
   // |point|, in client coordinates.
   virtual int GetNonClientComponent(const gfx::Point& point) = 0;
 
   // Mouse and key event handlers.
   virtual bool OnKeyEvent(const ui::KeyEvent& event) = 0;
   virtual bool OnMouseEvent(const ui::MouseEvent& event) = 0;
   virtual void OnMouseCaptureLost() = 0;
 
   virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) = 0;
   virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) = 0;
-  virtual ui::EventResult OnGestureEvent(ui::GestureEvent* event) = 0;
+  virtual void OnGestureEvent(ui::GestureEvent* event) = 0;
 
   // Runs the specified native command. Returns true if the command is handled.
   virtual bool ExecuteCommand(int command_id) = 0;
 
   // Returns the input method of the widget this delegate is associated with.
   // Note that this does not use the top level widget, so may return NULL
   // if the widget doesn't have input method.
   virtual InputMethod* GetInputMethodDirect() = 0;
 
   // Returns the child Layers of the Widgets layer that were created by Views.
   virtual const std::vector<ui::Layer*>& GetRootLayers() = 0;
 
   // Returns true if window has a hit-test mask.
   virtual bool HasHitTestMask() const = 0;
 
   // Provides the hit-test mask if HasHitTestMask above returns true.
   virtual void GetHitTestMask(gfx::Path* mask) const = 0;
 
   //
   virtual Widget* AsWidget() = 0;
   virtual const Widget* AsWidget() const = 0;
 };
 
 }  // namespace internal
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_NATIVE_WIDGET_DELEGATE_H_