base: Remove some unnecessary const scoped_refptr<>&.

base/thread_task_runner_handle.cc

 // Copyright (c) 2012 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.
 
 #include "base/thread_task_runner_handle.h"
 
 #include "base/lazy_instance.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_local.h"
 
@@ skipping 12 matching lines @@
   DCHECK(current);
   return current->task_runner_;
 }
 
 // static
 bool ThreadTaskRunnerHandle::IsSet() {
   return lazy_tls_ptr.Pointer()->Get() != NULL;
 }
 
 ThreadTaskRunnerHandle::ThreadTaskRunnerHandle(
-    const scoped_refptr<SingleThreadTaskRunner>& task_runner)
-    : task_runner_(task_runner) {
+    scoped_refptr<SingleThreadTaskRunner> task_runner)
+    : task_runner_(std::move(task_runner)) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!lazy_tls_ptr.Pointer()->Get());
   lazy_tls_ptr.Pointer()->Set(this);
 }
 
 ThreadTaskRunnerHandle::~ThreadTaskRunnerHandle() {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(lazy_tls_ptr.Pointer()->Get(), this);
   lazy_tls_ptr.Pointer()->Set(NULL);
 }
 
 }  // namespace base