Express audio delay more precisely in frames rather than milliseconds.

media/renderers/audio_renderer_impl.h

 // Copyright (c) 2012 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.
 
 // Audio rendering unit utilizing an AudioRendererSink to output data.
 //
 // This class lives inside three threads during it's lifetime, namely:
 // 1. Render thread
 //    Where the object is created.
 // 2. Media thread (provided via constructor)
@@ skipping 137 matching lines @@
   // |audio_bus|, it could be a sign that the pipeline is stalled or unable to
   // stream the data fast enough.  In such scenarios, the callee should zero out
   // unused portions of their buffer to play back silence.
   //
   // Render() updates the pipeline's playback timestamp. If Render() is
   // not called at the same rate as audio samples are played, then the reported
   // timestamp in the pipeline will be ahead of the actual audio playback. In
   // this case |audio_delay_milliseconds| should be used to indicate when in the
   // future should the filled buffer be played.
   int Render(AudioBus* audio_bus,
-             uint32_t audio_delay_milliseconds,
+             uint32_t frames_delayed,
              uint32_t frames_skipped) override;
   void OnRenderError() override;
 
   // Helper methods that schedule an asynchronous read from the decoder as long
   // as there isn't a pending read.
   //
   // Must be called on |task_runner_|.
   void AttemptRead();
   void AttemptRead_Locked();
   bool CanRead_Locked();
@@ skipping 115 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<AudioRendererImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioRendererImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_RENDERERS_AUDIO_RENDERER_IMPL_H_