Add the "virtual" keyword on method overrides that are missing it.

chrome/browser/worker_host/worker_service.h

 // Copyright (c) 2009 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_WORKER_HOST_WORKER_SERVICE_H_
 #define CHROME_BROWSER_WORKER_HOST_WORKER_SERVICE_H_
 #pragma once
 
 #include <list>
 
@@ skipping 124 matching lines @@
   bool CanCreateWorkerProcess(
       const WorkerProcessHost::WorkerInstance& instance);
 
   // Checks if the tab associated with the passed RenderView can create a
   // worker process based on the process limit when we're using a strategy of
   // one worker per process.
   bool TabCanCreateWorkerProcess(
       int renderer_id, int render_view_route_id, bool* hit_total_worker_limit);
 
   // NotificationObserver interface.
-  void Observe(NotificationType type,
-               const NotificationSource& source,
-               const NotificationDetails& details);
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
 
   // Notifies us that a process that's talking to a worker has shut down.
   void SenderShutdown(IPC::Message::Sender* sender);
 
   // Notifies us that a worker process has closed.
   void WorkerProcessDestroyed(WorkerProcessHost* process);
 
   // APIs for manipulating our set of pending shared worker instances.
   WorkerProcessHost::WorkerInstance* CreatePendingInstance(
       const GURL& url, const string16& name, bool off_the_record);
@@ skipping 10 matching lines @@
 
   // These are shared workers that have been looked up, but not created yet.
   // We need to keep a list of these to synchronously detect shared worker
   // URL mismatches when two pages launch shared workers simultaneously.
   WorkerProcessHost::Instances pending_shared_workers_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerService);
 };
 
 #endif  // CHROME_BROWSER_WORKER_HOST_WORKER_SERVICE_H_