patch from 1011683002 w/o audio thread fix

base/message_loop/incoming_task_queue.h

Index: base/message_loop/incoming_task_queue.h
diff --git a/base/message_loop/incoming_task_queue.h b/base/message_loop/incoming_task_queue.h
index 72e1f30282966de72b01a505a6144839a1d00643..020b26a5b77cfd9e3e226a422b809bf8f58c84f8 100644
--- a/base/message_loop/incoming_task_queue.h
+++ b/base/message_loop/incoming_task_queue.h
@@ -53,6 +53,12 @@ class BASE_EXPORT IncomingTaskQueue
   // Disconnects |this| from the parent message loop.
   void WillDestroyCurrentMessageLoop();
 
+  // This should be called when it's ready for scheduling work.
+  void StartScheduling();
+
+  // Returns true if this has no queued tasks.
+  bool empty();
+
  private:
   friend class RefCountedThreadSafe<IncomingTaskQueue>;
   virtual ~IncomingTaskQueue();
@@ -92,6 +98,9 @@ class BASE_EXPORT IncomingTaskQueue
   // if the incoming queue was not empty.
   const bool always_schedule_work_;
 
+  // False until StartScheduling() is called.
+  bool is_ready_for_scheduling_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(IncomingTaskQueue);
 };