Convert //extensions/browser from scoped_ptr to std::unique_ptr

extensions/browser/mojo/stash_backend.h

Index: extensions/browser/mojo/stash_backend.h
diff --git a/extensions/browser/mojo/stash_backend.h b/extensions/browser/mojo/stash_backend.h
index f374e00f9574ecb07614d90c2c6830255ee40524..a6d2515c2ffc914b9c24acd92a9b200db716135d 100644
--- a/extensions/browser/mojo/stash_backend.h
+++ b/extensions/browser/mojo/stash_backend.h
@@ -39,7 +39,7 @@ class StashBackend {
   void OnHandleReady();
 
   // The objects that have been stashed.
-  std::vector<scoped_ptr<StashEntry>> stashed_objects_;
+  std::vector<std::unique_ptr<StashEntry>> stashed_objects_;
 
   // The callback to call when a handle is readable.
   const base::Closure on_handle_readable_;