Some linked_ptr -> unique_ptr conversion in extensions/browser.

extensions/browser/external_provider_interface.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 EXTENSIONS_BROWSER_EXTERNAL_PROVIDER_INTERFACE_H_
 #define EXTENSIONS_BROWSER_EXTERNAL_PROVIDER_INTERFACE_H_
 
+#include <memory>
 #include <vector>
 
-#include "base/memory/linked_ptr.h"
 #include "extensions/common/manifest.h"
 
 class GURL;
 
 namespace base {
 class Version;
 }
 
 namespace extensions {
 
@@ skipping 68 matching lines @@
   virtual bool GetExtensionDetails(
       const std::string& id,
       Manifest::Location* location,
       std::unique_ptr<base::Version>* version) const = 0;
 
   // Determines if this provider had loaded the list of external extensions
   // from its source.
   virtual bool IsReady() const = 0;
 };
 
-typedef std::vector<linked_ptr<ExternalProviderInterface> >
-    ProviderCollection;
+using ProviderCollection =
+    std::vector<std::unique_ptr<ExternalProviderInterface>>;
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTERNAL_PROVIDER_INTERFACE_H_