Update VideoFrameScheduler API and add clockless and testing implementations.

media/filters/clockless_video_frame_scheduler.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/clockless_video_frame_scheduler.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/message_loop/message_loop_proxy.h"
+#include "media/base/video_frame.h"
+
+namespace media {
+
+ClocklessVideoFrameScheduler::ClocklessVideoFrameScheduler(
+    const DisplayCB& display_cb)
+    : display_cb_(display_cb) {
+}
+
+ClocklessVideoFrameScheduler::~ClocklessVideoFrameScheduler() {
+}
+
+void ClocklessVideoFrameScheduler::ScheduleVideoFrame(
+    const scoped_refptr<VideoFrame>& frame,
+    base::TimeTicks /* wall_ticks */,
+    const DoneCB& done_cb) {
+  display_cb_.Run(frame);
+  base::MessageLoopProxy::current()->PostTask(
+      FROM_HERE, base::Bind(done_cb, frame, DISPLAYED));
+}
+
+void ClocklessVideoFrameScheduler::Reset() {
+}
+
+}  // namespace media