Enable audio/video tag in content_shell

content/shell/shell_resource_context.h

 // Copyright (c) 2011 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 CONTENT_SHELL_SHELL_RESOURCE_CONTEXT_H_
 #define CONTENT_SHELL_SHELL_RESOURCE_CONTEXT_H_
 #pragma once
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "content/browser/resource_context.h"
+#include "media/audio/audio_manager.h"
 
 class ChromeBlobStorageContext;
 
 namespace content {
 
 class ShellURLRequestContextGetter;
 
 class ShellResourceContext : public content::ResourceContext {
  public:
   ShellResourceContext(
       ShellURLRequestContextGetter* getter,
-      ChromeBlobStorageContext* blob_storage_context);
+      ChromeBlobStorageContext* blob_storage_context,
+      AudioManager* audio_manager);
   virtual ~ShellResourceContext();
 
  private:
   virtual void EnsureInitialized() const OVERRIDE;
 
   void InitializeInternal();
 
   scoped_refptr<ShellURLRequestContextGetter> getter_;
   scoped_refptr<ChromeBlobStorageContext> blob_storage_context_;
+  scoped_refptr<AudioManager> audio_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(ShellResourceContext);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_SHELL_SHELL_RESOURCE_CONTEXT_H_