Update VideoFrameScheduler API and add clockless and testing implementations.

media/filters/video_frame_scheduler_impl.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 "media/filters/video_frame_scheduler_impl.h"
 
 #include <list>
 
 #include "base/single_thread_task_runner.h"
 #include "base/time/default_tick_clock.h"
@@ skipping 16 matching lines @@
     const scoped_refptr<VideoFrame>& frame,
     base::TimeTicks wall_ticks,
     const DoneCB& done_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!frame->end_of_stream());
   pending_frames_.push(PendingFrame(frame, wall_ticks, done_cb));
   ResetTimerIfNecessary();
 }
 
 void VideoFrameSchedulerImpl::Reset() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  while (!pending_frames_.empty()) {
-    pending_frames_.top().done_cb.Run(pending_frames_.top().frame, RESET);
-    pending_frames_.pop();
-  }
+  pending_frames_ = PendingFrameQueue();
+  timer_.Stop();
 }
 
 void VideoFrameSchedulerImpl::SetTickClockForTesting(
     scoped_ptr<base::TickClock> tick_clock) {
   tick_clock_.swap(tick_clock);
 }
 
 void VideoFrameSchedulerImpl::ResetTimerIfNecessary() {
   if (pending_frames_.empty()) {
     DCHECK(!timer_.IsRunning());
@@ skipping 47 matching lines @@
 bool VideoFrameSchedulerImpl::PendingFrame::operator<(
     const PendingFrame& other) const {
   // Flip the comparison as std::priority_queue<T>::top() returns the largest
   // element.
   //
   // Assume video frames with identical timestamps contain identical content.
   return wall_ticks > other.wall_ticks;
 }
 
 }  // namespace media