Remove some linked_ptr c/b/extension

chrome/browser/extensions/api/streams_private/streams_private_api.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_API_STREAMS_PRIVATE_STREAMS_PRIVATE_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_STREAMS_PRIVATE_STREAMS_PRIVATE_API_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 44 matching lines @@
 
   void AbortStream(const std::string& extension_id,
                    const GURL& stream_url,
                    const base::Closure& callback);
 
   // BrowserContextKeyedAPI implementation.
   static BrowserContextKeyedAPIFactory<StreamsPrivateAPI>* GetFactoryInstance();
 
  private:
   friend class BrowserContextKeyedAPIFactory<StreamsPrivateAPI>;
-  typedef std::map<std::string,
-                   std::map<GURL,
-                            linked_ptr<content::StreamHandle> > > StreamMap;
 
   // ExtensionRegistryObserver implementation.
   void OnExtensionUnloaded(content::BrowserContext* browser_context,
                            const Extension* extension,
                            UnloadedExtensionInfo::Reason reason) override;
 
   // BrowserContextKeyedAPI implementation.
   static const char* service_name() {
     return "StreamsPrivateAPI";
   }
   static const bool kServiceIsNULLWhileTesting = true;
   static const bool kServiceRedirectedInIncognito = true;
 
   content::BrowserContext* const browser_context_;
+  using StreamMap =
+      std::map<std::string,
+               std::map<GURL, std::unique_ptr<content::StreamHandle>>>;
   StreamMap streams_;
 
   // Listen to extension unloaded notifications.
   ScopedObserver<ExtensionRegistry, ExtensionRegistryObserver>
       extension_registry_observer_;
 
   base::WeakPtrFactory<StreamsPrivateAPI> weak_ptr_factory_;
 
 };
 
@@ skipping 10 matching lines @@
 
  private:
   void OnClose();
 
   std::string stream_url_;
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_STREAMS_PRIVATE_STREAMS_PRIVATE_API_H_