x11: Simplify some more event-rewrite code.

chrome/browser/chromeos/events/event_rewriter.h

 // Copyright 2014 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_EVENT_REWRITER_H_
 #define CHROME_BROWSER_CHROMEOS_EVENTS_EVENT_REWRITER_H_
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_pump_observer.h"
 #include "chrome/browser/chromeos/device_hierarchy_observer.h"
-#include "ui/aura/window_tree_host_observer.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 
 class PrefService;
 typedef union _XEvent XEvent;
 
-namespace aura {
-class RootWindow;
-}
-
 namespace chromeos {
 class KeyboardDrivenEventRewriter;
 namespace input_method {
 class XKeyboard;
 }
 
-class EventRewriter : public aura::WindowTreeHostObserver,
-                      public DeviceHierarchyObserver,
+class EventRewriter : public DeviceHierarchyObserver,
                       public base::MessagePumpObserver {
  public:
   enum DeviceType {
     kDeviceUnknown = 0,
     kDeviceAppleKeyboard,
   };
 
   EventRewriter();
   virtual ~EventRewriter();
 
@@ skipping 16 matching lines @@
     xkeyboard_for_testing_ = xkeyboard;
   }
 
   // Gets DeviceType from the |device_name|.
   static DeviceType GetDeviceType(const std::string& device_name);
 
  private:
   friend class EventRewriterAshTest;
   friend class EventRewriterTest;
 
-  // aura::WindowTreeHostObserver overrides:
-  virtual void OnKeyboardMappingChanged(
-      const aura::WindowTreeHost* host) OVERRIDE;
-
   // base::MessagePumpObserver overrides:
   virtual base::EventStatus WillProcessEvent(
       const base::NativeEvent& event) OVERRIDE;
   virtual void DidProcessEvent(const base::NativeEvent& event) OVERRIDE;
 
   // DeviceHierarchyObserver overrides:
   virtual void DeviceHierarchyChanged() OVERRIDE {}
   virtual void DeviceAdded(int device_id) OVERRIDE;
   virtual void DeviceRemoved(int device_id) OVERRIDE;
   virtual void DeviceKeyPressedOrReleased(int device_id) OVERRIDE;
@@ skipping 120 matching lines @@
       keyboard_driven_event_rewriter_;
 
   const PrefService* pref_service_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(EventRewriter);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_EVENTS_EVENT_REWRITER_H_