cc: Use correct message loop proxy in BlockingTaskRunner

cc/trees/proxy.cc

 // Copyright 2011 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 "cc/trees/proxy.h"
 
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/single_thread_task_runner.h"
+#include "cc/trees/blocking_task_runner.h"
 
 namespace cc {
 
 base::SingleThreadTaskRunner* Proxy::MainThreadTaskRunner() const {
   return main_task_runner_.get();
 }
 
 bool Proxy::HasImplThread() const { return !!impl_task_runner_.get(); }
 
 base::SingleThreadTaskRunner* Proxy::ImplThreadTaskRunner() const {
@@ skipping 43 matching lines @@
 
 #if DCHECK_IS_ON
 void Proxy::SetMainThreadBlocked(bool is_main_thread_blocked) {
   is_main_thread_blocked_ = is_main_thread_blocked;
 }
 #endif
 
 Proxy::Proxy(scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
              scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner)
 #if !DCHECK_IS_ON
-    : main_task_runner_(main_task_runner), impl_task_runner_(impl_task_runner) {
+    : main_task_runner_(main_task_runner),
+      impl_task_runner_(impl_task_runner),
+      blocking_main_thread_task_runner_(BlockingTaskRunner::current()) {
 #else
     : main_task_runner_(main_task_runner),
       impl_task_runner_(impl_task_runner),
+      blocking_main_thread_task_runner_(BlockingTaskRunner::current()),
       main_thread_id_(base::PlatformThread::CurrentId()),
       impl_thread_is_overridden_(false),
       is_main_thread_blocked_(false) {
 #endif
+  blocking_main_thread_task_runner_->SetTaskRunner(main_task_runner_);
 }
 
 Proxy::~Proxy() {
   DCHECK(IsMainThread());
+  blocking_main_thread_task_runner_->SetTaskRunner(
+      base::MessageLoopProxy::current());
 }
 
 }  // namespace cc