Convert //extensions/{common,shell} from scoped_ptr to std::unique_ptr

extensions/common/file_util.h

Index: extensions/common/file_util.h
diff --git a/extensions/common/file_util.h b/extensions/common/file_util.h
index 3fda56ad8f0d04e5e98548197d0e098c357fe557..5fcf4e9a20d5f1e98b777d73e5c4a2080ebe3472 100644
--- a/extensions/common/file_util.h
+++ b/extensions/common/file_util.h
@@ -62,12 +62,12 @@ scoped_refptr<Extension> LoadExtension(const base::FilePath& extension_root,
 
 // Loads an extension manifest from the specified directory. Returns NULL
 // on failure, with a description of the error in |error|.
-scoped_ptr<base::DictionaryValue> LoadManifest(
+std::unique_ptr<base::DictionaryValue> LoadManifest(
     const base::FilePath& extension_root,
     std::string* error);
 
 // Convenience overload for specifying a manifest filename.
-scoped_ptr<base::DictionaryValue> LoadManifest(
+std::unique_ptr<base::DictionaryValue> LoadManifest(
     const base::FilePath& extension_root,
     const base::FilePath::CharType* manifest_filename,
     std::string* error);