base: Do not allow MessagePumpObservers to consume events.

chrome/browser/chromeos/events/xinput_hierarchy_changed_event_listener.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 CHROME_BROWSER_CHROMEOS_EVENTS_XINPUT_HIERARCHY_CHANGED_EVENT_LISTENER_H_
 #define CHROME_BROWSER_CHROMEOS_EVENTS_XINPUT_HIERARCHY_CHANGED_EVENT_LISTENER_H_
 
 #include "base/memory/singleton.h"
 #include "base/message_loop/message_loop.h"
 #include "base/observer_list.h"
@@ skipping 19 matching lines @@
 
  private:
   // Defines the delete on exit Singleton traits we like.  Best to have this
   // and const/dest private as recommended for Singletons.
   friend struct DefaultSingletonTraits<XInputHierarchyChangedEventListener>;
 
   XInputHierarchyChangedEventListener();
   virtual ~XInputHierarchyChangedEventListener();
 
   // MessageLoopForUI::Observer overrides.
-  virtual base::EventStatus WillProcessEvent(
-      const base::NativeEvent& event) OVERRIDE;
+  virtual void WillProcessEvent(const base::NativeEvent& event) OVERRIDE;
   virtual void DidProcessEvent(const base::NativeEvent& event) OVERRIDE;
 
   // Returns true if the event was processed, false otherwise.
   void ProcessedXEvent(XEvent* xevent);
 
   // Notify observers that a device has been added/removed.
   void NotifyDeviceHierarchyChanged();
 
   bool stopped_;
 
   ObserverList<DeviceHierarchyObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(XInputHierarchyChangedEventListener);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_EVENTS_XINPUT_HIERARCHY_CHANGED_EVENT_LISTENER_H_