Change who allocated the MediaPipe's shared buffer.

examples/audio_play_test/play_tone.cc

 // Copyright 2015 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 <math.h>
 #include <memory>
 
 #include "mojo/public/c/system/main.h"
 #include "mojo/public/cpp/application/application_delegate.h"
 #include "mojo/public/cpp/application/application_impl.h"
@@ skipping 103 matching lines @@
   sink_desc.reset();
 
   // Grab the rate control interface for our audio renderer.
   audio_track_->GetRateControl(GetProxy(&rate_control_));
   rate_control_.set_connection_error_handler([this]() {
     OnConnectionError("rate_control");
   });
 
   // Configure our sink for 16-bit 48KHz mono.
   AudioTrackConfigurationPtr cfg = AudioTrackConfiguration::New();
-  cfg->max_frames = USecToBytes(BUF_DEPTH_USEC) / FRAME_BYTES;
 
   LpcmMediaTypeDetailsPtr pcm_cfg = LpcmMediaTypeDetails::New();
   pcm_cfg->sample_format     = LpcmSampleFormat::SIGNED_16;
   pcm_cfg->channels          = 1;
   pcm_cfg->frames_per_second = SAMP_FREQ;
 
   cfg->media_type = MediaType::New();
   cfg->media_type->scheme = MediaTypeScheme::LPCM;
   cfg->media_type->details = MediaTypeDetails::New();
   cfg->media_type->details->set_lpcm(pcm_cfg.Pass());
 
   MediaPipePtr pipe;
   audio_track_->Configure(cfg.Pass(), GetProxy(&pipe));
 
   // Now that the configuration request is in-flight and we our media pipe
   // proxy, pass its interface to our circular buffer helper, set up our
   // high/low water marks, register our callback, and start to buffer our audio.
   audio_pipe_.reset(new CircularBufferMediaPipeAdapter(pipe.Pass()));
+  audio_pipe_->Init(USecToBytes(BUF_DEPTH_USEC));
   audio_pipe_->SetSignalCallback(
   [this](MediaResult res) -> void {
     GenerateToneCbk(res);
   });
   audio_pipe_->SetWatermarks(USecToBytes(BUF_HI_WATER_USEC),
                              USecToBytes(BUF_LO_WATER_USEC));
 }
 
 void PlayToneApp::GenerateToneCbk(MediaResult res) {
   using MappedPacket = CircularBufferMediaPipeAdapter::MappedPacket;
@@ skipping 93 matching lines @@
 }  // namespace audio
 }  // namespace media
 }  // namespace mojo
 
 MojoResult MojoMain(MojoHandle app_request) {
   mojo::ApplicationRunner runner(
       std::unique_ptr<mojo::media::audio::examples::PlayToneApp>(
           new mojo::media::audio::examples::PlayToneApp()));
   return runner.Run(app_request);
 }