Delete media::Synchronizer since it's never been used.

Code is nearly two years old and has yet to be used anywhere.  My original intention was to use it to extract the synchronizing code from VideoRendererBase, but looks like I never got around to it.

BUG=54110
TEST=compiles

Review URL: http://codereview.chromium.org/4823002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@65987 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 0 insertions, 149 deletions

diff --git a/media/base/synchronizer.cc b/media/base/synchronizer.cc
deleted file mode 100644
index abeb8ad..0000000
--- a/media/base/synchronizer.cc
+++ /dev/null
@@ -1,90 +0,0 @@
-// Copyright (c) 2009 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/base/synchronizer.h"
-
-namespace media {
-
-const int64 Synchronizer::kMinFrameDelayUs = 0;
-const int64 Synchronizer::kMaxFrameDelayUs = 250000;
-
-Synchronizer::Synchronizer() {
-}
-
-Synchronizer::~Synchronizer() {
-}
-
-void Synchronizer::StartRendering() {
-  rendering_start_ = base::TimeTicks::Now();
-}
-
-void Synchronizer::StopRendering() {
-  rendering_stop_ = base::TimeTicks::Now();
-}
-
-void Synchronizer::CalculateDelay(base::TimeDelta time,
-                                  const StreamSample* now,
-                                  const StreamSample* next,
-                                  base::TimeDelta* delay_out,
-                                  bool* should_skip_out) {
-  // How long rendering took.
-  base::TimeDelta render_delta = rendering_stop_ - rendering_start_;
-
-  // The duration to display the sample |now|.
-  base::TimeDelta duration = now->GetDuration();
-
-  // The presentation timestamp (pts) of the sample |now|.
-  base::TimeDelta now_pts = now->GetTimestamp();
-
-  // The presentation timestamp (pts) of the next sample.
-  base::TimeDelta next_pts;
-
-  // If we were provided the next sample in the stream |next|, use it to
-  // calculate the actual sample duration as opposed to the expected duration
-  // provided by the current sample |now|.
-  //
-  // We also use |next| to get the exact next timestamp as opposed to assuming
-  // it will be |now| + |now|'s duration, which may not always be true.
-  if (next) {
-    next_pts = next->GetTimestamp();
-    duration = next_pts - now_pts;
-
-    // Timestamps appear out of order, so skip this frame.
-    if (duration.InMicroseconds() < 0) {
-      *delay_out = base::TimeDelta();
-      *should_skip_out = true;
-      return;
-    }
-  } else {
-    // Assume next presentation timestamp is |now| + |now|'s duration.
-    next_pts = now_pts + duration;
-  }
-
-  base::TimeDelta sleep;
-  if (time == last_time_) {
-    // The audio time has not changed. To avoid sudden bursts of video after
-    // we get audio timing information, we try and guess the current time
-    // using the duration of the frame.
-    sleep = duration - render_delta;
-    if (sleep.InMicroseconds() < kMinFrameDelayUs) {
-      sleep = base::TimeDelta::FromMicroseconds(kMinFrameDelayUs);
-    }
-  } else {
-    // The audio time has changed.  The amount of time to delay is equal to
-    // the time until the next sample from now minus how long it takes to
-    // render, clamped to within the min/max frame delay constants.
-    sleep = next_pts - time - render_delta;
-    if (sleep.InMicroseconds() < kMinFrameDelayUs) {
-      sleep = base::TimeDelta::FromMicroseconds(kMinFrameDelayUs);
-    } else if (sleep.InMicroseconds() > kMaxFrameDelayUs) {
-      sleep = base::TimeDelta::FromMicroseconds(kMaxFrameDelayUs);
-    }
-  }
-  last_time_ = time;
-
-  *delay_out = sleep;
-  *should_skip_out = false;
-}
-
-}  // namespace media
diff --git a/media/base/synchronizer.h b/media/base/synchronizer.h
deleted file mode 100644
index 122c32f..0000000
--- a/media/base/synchronizer.h
+++ /dev/null
@@ -1,59 +0,0 @@
-// Copyright (c) 2009 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.
-
-// Utility class for video renderers to help synchronize against a reference
-// clock while also taking rendering duration into account.
-//
-// Video renderers should maintain an instance of this object for the entire
-// lifetime since Synchronizer maintains internal state to improve playback.
-//
-// VideoRenderer usage is as follows:
-//   Receive a new frame from the decoder
-//   Call StartRendering
-//   Perform colour space conversion and render the frame
-//   Call StopRendering
-//   Call CalculateDelay passing in the rendered frame and optional next frame
-//   Issue delayed task or sleep on thread for returned amount of time
-
-#ifndef MEDIA_BASE_SYNCHRONIZER_H_
-#define MEDIA_BASE_SYNCHRONIZER_H_
-
-#include "base/basictypes.h"
-#include "base/time.h"
-#include "media/base/buffers.h"
-
-namespace media {
-
-class Synchronizer {
- public:
-  Synchronizer();
-  ~Synchronizer();
-
-  // Starts the rendering timer.
-  void StartRendering();
-
-  // Stops the rendering timer.
-  void StopRendering();
-
-  // Calculates the appropriate amount of delay in microseconds given the
-  // current time, the current sample and the next sample (may be NULL,
-  // but is recommended to pass in for smoother playback).
-  void CalculateDelay(base::TimeDelta time, const StreamSample* now,
-                      const StreamSample* next, base::TimeDelta* delay_out,
-                      bool* should_skip_out);
-
- private:
-  static const int64 kMinFrameDelayUs;
-  static const int64 kMaxFrameDelayUs;
-
-  base::TimeTicks rendering_start_;
-  base::TimeTicks rendering_stop_;
-  base::TimeDelta last_time_;
-
-  DISALLOW_COPY_AND_ASSIGN(Synchronizer);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_BASE_SYNCHRONIZER_H_