cc: Remove some unnecessary const scoped_refptr&.

cc/output/texture_mailbox_deleter.h

Index: cc/output/texture_mailbox_deleter.h
diff --git a/cc/output/texture_mailbox_deleter.h b/cc/output/texture_mailbox_deleter.h
index 051ad34d88b6eb8ebe3b38b0d440757ecd15a03c..f25661db99562d8e58fc4ed208f0a23ad46c83fc 100644
--- a/cc/output/texture_mailbox_deleter.h
+++ b/cc/output/texture_mailbox_deleter.h
@@ -27,7 +27,7 @@ class CC_EXPORT TextureMailboxDeleter {
   // task_runner corresponds with the thread the delete task should be posted
   // to. If null, the delete will happen on the calling thread.
   explicit TextureMailboxDeleter(
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
   ~TextureMailboxDeleter();
 
   // Returns a Callback that can be used as the ReleaseCallback for a
@@ -38,7 +38,7 @@ class CC_EXPORT TextureMailboxDeleter {
   // become a no-op and the texture will be deleted immediately on the
   // impl thread, along with dropping the reference to the ContextProvider.
   scoped_ptr<SingleReleaseCallback> GetReleaseCallback(
-      const scoped_refptr<ContextProvider>& context_provider,
+      scoped_refptr<ContextProvider> context_provider,
       unsigned texture_id);
 
  private: