Remove some linked_ptr c/b/extension

chrome/browser/extensions/api/streams_private/streams_private_api.h

Index: chrome/browser/extensions/api/streams_private/streams_private_api.h
diff --git a/chrome/browser/extensions/api/streams_private/streams_private_api.h b/chrome/browser/extensions/api/streams_private/streams_private_api.h
index e2e2ab84aa340079bea4fae328b0496120910342..3d987d480d8f8454b0e81e071a1a77865265de44 100644
--- a/chrome/browser/extensions/api/streams_private/streams_private_api.h
+++ b/chrome/browser/extensions/api/streams_private/streams_private_api.h
@@ -62,9 +62,6 @@ class StreamsPrivateAPI : public BrowserContextKeyedAPI,
 
  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,
@@ -79,6 +76,9 @@ class StreamsPrivateAPI : public BrowserContextKeyedAPI,
   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.