Implement frame attribution (FrameBlamer)

components/scheduler/base/task_queue.h

 // 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.
 
 #ifndef COMPONENTS_SCHEDULER_BASE_TASK_QUEUE_H_
 #define COMPONENTS_SCHEDULER_BASE_TASK_QUEUE_H_
 
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/single_thread_task_runner.h"
+#include "base/trace_event/trace_event.h"
 #include "components/scheduler/scheduler_export.h"
 
+namespace base {
+namespace trace_event {
+class BlameContext;
+}
+}
+
 namespace scheduler {
 class TimeDomain;
 
 class SCHEDULER_EXPORT TaskQueue : public base::SingleThreadTaskRunner {
  public:
   TaskQueue() {}
 
   // Unregisters the task queue after which no tasks posted to it will run and
   // the TaskQueueManager's reference to it will be released soon.
   virtual void UnregisterTaskQueue() = 0;
@@ skipping 154 matching lines @@
   // |may_post_dowork|.
   virtual void PumpQueue(bool may_post_dowork) = 0;
 
   // These functions can only be called on the same thread that the task queue
   // manager executes its tasks on.
   virtual void AddTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) = 0;
   virtual void RemoveTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) = 0;
 
+  // Set the blame context which is entered and left while executing tasks from
+  // this task queue. |blame_context| must be null or outlive this task queue.

[alex clarke (OOO till 29th), 2016/03/21 14:38:36]

Please mention this is main thread only.

[Sami, 2016/03/21 15:18:05]

Done.

+  virtual void SetBlameContext(
+      base::trace_event::BlameContext* blame_context) = 0;
+
   // Removes the task queue from the previous TimeDomain and adds it to
   // |domain|.  This is a moderately expensive operation.
   virtual void SetTimeDomain(TimeDomain* domain) = 0;
 
   // Returns the queue's current TimeDomain.  Can be called from any thread.
   virtual TimeDomain* GetTimeDomain() const = 0;
 
  protected:
   ~TaskQueue() override {}
 
   DISALLOW_COPY_AND_ASSIGN(TaskQueue);
 };
 
 }  // namespace scheduler
 
 #endif  // COMPONENTS_SCHEDULER_BASE_TASK_QUEUE_H_