Add ScopedAllowWait to TaskGraphRunner to Avoid Crash in Shutdown

cc/resources/task_graph_runner.cc

 // Copyright 2014 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/resources/task_graph_runner.h"
 
 #include <algorithm>
 
 #include "base/strings/stringprintf.h"
 #include "base/threading/thread_restrictions.h"
@@ skipping 272 matching lines @@
   }
 }
 
 void TaskGraphRunner::WaitForTasksToFinishRunning(NamespaceToken token) {
   TRACE_EVENT0("cc", "TaskGraphRunner::WaitForTasksToFinishRunning");
 
   DCHECK(token.IsValid());
 
   {
     base::AutoLock lock(lock_);
+    base::ThreadRestrictions::ScopedAllowWait allow_wait;
 
     TaskNamespaceMap::const_iterator it = namespaces_.find(token.id_);
     if (it == namespaces_.end())
       return;
 
     const TaskNamespace& task_namespace = it->second;
 
     while (!HasFinishedRunningTasksInNamespace(&task_namespace))
       has_namespaces_with_finished_running_tasks_cv_.Wait();
 
@@ skipping 168 matching lines @@
 
   // Finally add task to |completed_tasks_|.
   task_namespace->completed_tasks.push_back(task);
 
   // If namespace has finished running all tasks, wake up origin thread.
   if (HasFinishedRunningTasksInNamespace(task_namespace))
     has_namespaces_with_finished_running_tasks_cv_.Signal();
 }
 
 }  // namespace cc