Convert string16 to base::string16 in content.

content/renderer/media/webcontentdecryptionmodule_impl.h

 // Copyright 2013 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_RENDERER_MEDIA_WEBCONTENTDECRYPTIONMODULE_IMPL_H_
 #define CONTENT_RENDERER_MEDIA_WEBCONTENTDECRYPTIONMODULE_IMPL_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
 #include "third_party/WebKit/public/platform/WebContentDecryptionModule.h"
 
 namespace media {
 class MediaKeys;
 }
 
 namespace content {
 
 class WebContentDecryptionModuleSessionImpl;
 class ReferenceIdAdapter;
 
 class WebContentDecryptionModuleImpl
     : public blink::WebContentDecryptionModule {
  public:
-  static WebContentDecryptionModuleImpl* Create(const string16& key_system);
+  static WebContentDecryptionModuleImpl* Create(
+      const base::string16& key_system);
 
   virtual ~WebContentDecryptionModuleImpl();
 
   // blink::WebContentDecryptionModule implementation.
   virtual blink::WebContentDecryptionModuleSession* createSession(
       blink::WebContentDecryptionModuleSession::Client* client);
 
  private:
   // Takes ownership of |media_keys| and |adapter|.
   WebContentDecryptionModuleImpl(scoped_ptr<media::MediaKeys> media_keys,
                                  scoped_ptr<ReferenceIdAdapter> adapter);
 
   // Called when a WebContentDecryptionModuleSessionImpl is closed.
   void OnSessionClosed(uint32 reference_id);
 
   scoped_ptr<media::MediaKeys> media_keys_;
   scoped_ptr<ReferenceIdAdapter> adapter_;
 
   DISALLOW_COPY_AND_ASSIGN(WebContentDecryptionModuleImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_WEBCONTENTDECRYPTIONMODULE_IMPL_H_