Add skeleton implementation of ExtensionPushMessagingEventRouter.

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index 7e082c88fd58c0b983d6bea6cd99463c1ac4e842..d4b07c36728afc30837bd79a7134ae3f2a8dce51 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -73,6 +73,7 @@ class CrxInstaller;
 class Extension;
 class ExtensionCookiesEventRouter;
 class ExtensionManagedModeEventRouter;
+class ExtensionPushMessagingEventRouter;
 class ExtensionSyncData;
 class ExtensionSystem;
 class ExtensionUpdater;
@@ -516,6 +517,10 @@ class ExtensionService
   }
 #endif
 
+  extensions::ExtensionPushMessagingEventRouter* push_messaging_event_router() {
+    return push_messaging_event_router_.get();
+  }
+
   // Notify the frontend that there was an error loading an extension.
   // This method is public because UnpackedInstaller and InstalledLoader
   // can post to here.
@@ -814,6 +819,9 @@ class ExtensionService
 
   scoped_ptr<ExtensionManagementEventRouter> management_event_router_;
 
+  scoped_ptr<extensions::ExtensionPushMessagingEventRouter>
+      push_messaging_event_router_;
+
   scoped_ptr<extensions::WebNavigationEventRouter> web_navigation_event_router_;
 
   scoped_ptr<ExtensionFontSettingsEventRouter> font_settings_event_router_;