Switch audio synchronization from sleep() based to select() based.

ppapi/proxy/ppb_audio_proxy.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/proxy/ppb_audio_proxy.h"
 
 #include "base/compiler_specific.h"
 #include "base/threading/simple_thread.h"
-#include "media/audio/shared_memory_util.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_audio.h"
 #include "ppapi/c/ppb_audio_config.h"
 #include "ppapi/c/ppb_var.h"
 #include "ppapi/proxy/enter_proxy.h"
 #include "ppapi/proxy/plugin_dispatcher.h"
 #include "ppapi/proxy/ppapi_messages.h"
 #include "ppapi/shared_impl/api_id.h"
 #include "ppapi/shared_impl/platform_file.h"
 #include "ppapi/shared_impl/ppapi_globals.h"
@@ skipping 235 matching lines @@
                                            &shared_memory,
                                            &audio_buffer_length);
   }
 
   // Send all the values, even on error. This simplifies some of our cleanup
   // code since the handles will be in the other process and could be
   // inconvenient to clean up. Our IPC code will automatically handle this for
   // us, as long as the remote side always closes the handles it receives
   // (in OnMsgNotifyAudioStreamCreated), even in the failure case.
   SerializedHandle fd_wrapper(SerializedHandle::SOCKET, socket_handle);
-
-  // Note that we must call TotalSharedMemorySizeInBytes because
-  // Audio allocates extra space in shared memory for book-keeping, so the
-  // actual size of the shared memory buffer is larger than audio_buffer_length.
-  // When sending to NaCl, NaClIPCAdapter expects this size to match the size
-  // of the full shared memory buffer.
-  SerializedHandle handle_wrapper(
-      shared_memory,
-      media::TotalSharedMemorySizeInBytes(audio_buffer_length));
+  SerializedHandle handle_wrapper(shared_memory, audio_buffer_length);
   dispatcher()->Send(new PpapiMsg_PPBAudio_NotifyAudioStreamCreated(
       API_ID_PPB_AUDIO, resource, result_code, fd_wrapper, handle_wrapper));
 }
 
 int32_t PPB_Audio_Proxy::GetAudioConnectedHandles(
     const HostResource& resource,
     IPC::PlatformFileForTransit* foreign_socket_handle,
     base::SharedMemoryHandle* foreign_shared_memory_handle,
     uint32_t* shared_memory_length) {
   // Get the audio interface which will give us the handles.
@@ skipping 42 matching lines @@
   if (enter.failed() || result_code != PP_OK) {
     // The caller may still have given us these handles in the failure case.
     // The easiest way to clean these up is to just put them in the objects
     // and then close them. This failure case is not performance critical.
     base::SyncSocket temp_socket(
         IPC::PlatformFileForTransitToPlatformFile(socket_handle.descriptor()));
     base::SharedMemory temp_mem(handle.shmem(), false);
   } else {
     EnterResourceNoLock<PPB_AudioConfig_API> config(
         static_cast<Audio*>(enter.object())->GetCurrentConfig(), true);
-    // See the comment above about how we must call
-    // TotalSharedMemorySizeInBytes to get the actual size of the buffer. Here,
-    // we must call PacketSizeInBytes to get back the size of the audio buffer,
-    // excluding the bytes that audio uses for book-keeping.
     static_cast<Audio*>(enter.object())->SetStreamInfo(
-        enter.resource()->pp_instance(), handle.shmem(),
-        media::PacketSizeInBytes(handle.size()),
+        enter.resource()->pp_instance(), handle.shmem(), handle.size(),
         IPC::PlatformFileForTransitToPlatformFile(socket_handle.descriptor()),
         config.object()->GetSampleRate(),
         config.object()->GetSampleFrameCount());
   }
 }
 
 }  // namespace proxy
 }  // namespace ppapi