Move ExtensionHost into extensions namespace

chrome/browser/extensions/event_router.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_EXTENSIONS_EVENT_ROUTER_H_
 #define CHROME_BROWSER_EXTENSIONS_EVENT_ROUTER_H_
 
 #include <map>
 #include <set>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/ref_counted.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/event_listener_map.h"
 #include "chrome/common/extensions/event_filtering_info.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "ipc/ipc_sender.h"
 
 class GURL;
-class ExtensionHost;
 class ExtensionDevToolsManager;
 class Profile;
 
 namespace content {
 class RenderProcessHost;
 }
 
 namespace extensions {
 class Extension;
+class ExtensionHost;
+
 struct Event;
 
 class EventRouter : public content::NotificationObserver,
                     public EventListenerMap::Delegate {
  public:
   // These constants convey the state of our knowledge of whether we're in
   // a user-caused gesture as part of DispatchEvent.
   enum UserGestureState {
     USER_GESTURE_UNKNOWN = 0,
     USER_GESTURE_ENABLED = 1,
@@ skipping 232 matching lines @@
         Profile* restrict_to_profile,
         EventRouter::UserGestureState user_gesture,
         const EventFilteringInfo& info);
 
   ~Event();
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EVENT_ROUTER_H_