events: Update mouse-event handlers to not return EventResult.

ash/tooltips/tooltip_controller.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 ASH_TOOLTIPS_TOOLTIP_CONTROLLER_H_
 #define ASH_TOOLTIPS_TOOLTIP_CONTROLLER_H_
 
 #include "ash/ash_export.h"
 #include "ash/wm/session_state_observer.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 27 matching lines @@
  public:
   explicit TooltipController(aura::client::DragDropClient* drag_drop_client);
   virtual ~TooltipController();
 
   // Overridden from aura::client::TooltipClient.
   virtual void UpdateTooltip(aura::Window* target) OVERRIDE;
   virtual void SetTooltipsEnabled(bool enable) OVERRIDE;
 
   // Overridden from ui::EventHandler.
   virtual void OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
-  virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
+  virtual void OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
   virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
 
   // Overridden from SessionStateController.
   virtual void OnSessionStateEvent(SessionStateObserver::EventType event)
       OVERRIDE;
 
   // Overridden from aura::WindowObserver.
   virtual void OnWindowDestroyed(aura::Window* window) OVERRIDE;
 
   gfx::Point mouse_location() const { return curr_mouse_loc_; }
@@ skipping 51 matching lines @@
 
   bool tooltips_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(TooltipController);
 };
 
 }  // namespace internal
 }  // namespace ash
 
 #endif  // ASH_TOOLTIPS_TOOLTIP_CONTROLLER_H_