Forward the number of skipped frames by the OS in audio playout.

ppapi/shared_impl/ppb_audio_shared.cc

 // 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.
 
 #include "ppapi/shared_impl/ppb_audio_shared.h"
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
+#include "media/audio/audio_parameters.h"
 #include "ppapi/nacl_irt/public/irt_ppapi.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
 #include "ppapi/shared_impl/ppb_audio_config_shared.h"
 #include "ppapi/shared_impl/proxy_lock.h"
 
 namespace ppapi {
 
 namespace {
 bool g_nacl_mode = false;
 // Because this is static, the function pointers will be NULL initially.
@@ skipping 86 matching lines @@
       kAudioOutputChannels * (kBitsPerAudioOutputSample / 8) * sample_rate;
   buffer_index_ = 0;
 
   if (!shared_memory_->Map(shared_memory_size_)) {
     PpapiGlobals::Get()->LogWithSource(
         instance,
         PP_LOGLEVEL_WARNING,
         std::string(),
         "Failed to map shared memory for PPB_Audio_Shared.");
   } else {
-    audio_bus_ = media::AudioBus::WrapMemory(
-        kAudioOutputChannels, sample_frame_count, shared_memory_->memory());
+    DCHECK_EQ(shared_memory_size_,
+              sizeof(media::AudioOutputBufferParameters) +
+                  media::AudioBus::CalculateMemorySize(kAudioOutputChannels,
+                                                       sample_frame_count));
+    media::AudioOutputBuffer* buffer =
+        reinterpret_cast<media::AudioOutputBuffer*>(shared_memory_->memory());
+    audio_bus_ = media::AudioBus::WrapMemory(kAudioOutputChannels,
+                                             sample_frame_count, buffer->audio);
     // Setup integer audio buffer for user audio data.
     client_buffer_size_bytes_ = audio_bus_->frames() * audio_bus_->channels() *
                                 kBitsPerAudioOutputSample / 8;
     client_buffer_.reset(new uint8_t[client_buffer_size_bytes_]);
   }
 
   StartThread();
 }
 
 void PPB_Audio_Shared::StartThread() {
@@ skipping 106 matching lines @@
     // Let the other end know which buffer we just filled.  The buffer index is
     // used to ensure the other end is getting the buffer it expects.  For more
     // details on how this works see AudioSyncReader::WaitUntilDataIsReady().
     size_t bytes_sent = socket_->Send(&buffer_index_, sizeof(buffer_index_));
     if (bytes_sent != sizeof(buffer_index_))
       break;
   }
 }
 
 }  // namespace ppapi