cc: Implement states for Task for stricter control.

cc/raster/single_thread_task_graph_runner.cc

 // Copyright 2015 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/raster/single_thread_task_graph_runner.h"
 
 #include <stdint.h>
 
 #include <string>
 
@@ skipping 130 matching lines @@
              pair) { return !pair.second.empty(); });
 
   if (found == ready_to_run_namespaces.cend()) {
     return false;
   }
 
   const uint16_t category = found->first;
   auto prioritized_task = work_queue_.GetNextTaskToRun(category);
   Task* task = prioritized_task.task;
 
-  // Call WillRun() before releasing |lock_| and running task.
-  task->WillRun();
-
   {
     base::AutoUnlock unlock(lock_);
     task->RunOnWorkerThread();
   }
 
-  // This will mark task as finished running.
-  task->DidRun();
-
   work_queue_.CompleteTask(prioritized_task);
 
   // If namespace has finished running all tasks, wake up origin thread.
   if (work_queue_.HasFinishedRunningTasksInNamespace(
           prioritized_task.task_namespace))
     has_namespaces_with_finished_running_tasks_cv_.Signal();
 
   return true;
 }
 
 }  // namespace cc