Remove "high"-latency audio code path

content/common/media/audio_messages.h

 // Copyright (c) 2011 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.
 
 // IPC messages for the audio.
 // Multiply-included message file, hence no include guard.
 
 #include "base/basictypes.h"
 #include "base/shared_memory.h"
 #include "base/sync_socket.h"
@@ skipping 18 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(format)
   IPC_STRUCT_TRAITS_MEMBER(channel_layout)
   IPC_STRUCT_TRAITS_MEMBER(sample_rate)
   IPC_STRUCT_TRAITS_MEMBER(bits_per_sample)
   IPC_STRUCT_TRAITS_MEMBER(samples_per_packet)
   IPC_STRUCT_TRAITS_MEMBER(channels)
 IPC_STRUCT_TRAITS_END()
 
 // Messages sent from the browser to the renderer.
 
-// Sent by AudioRendererHost to renderer to request an audio packet.
-IPC_MESSAGE_CONTROL2(AudioMsg_RequestPacket,
-                     int /* stream id */,
-                     AudioBuffersState)
-
-// Tell the renderer process that the audio stream has been created, renderer
-// process would be given a ShareMemoryHandle that it should write to from
-// then on.
-IPC_MESSAGE_CONTROL3(AudioMsg_NotifyStreamCreated,
-                     int /* stream id */,
-                     base::SharedMemoryHandle /* handle */,
-                     uint32 /* length */)
-
-// Tell the renderer process that a low latency audio stream has been created,
-// renderer process would be given a SyncSocket that it should write to from
-// then on.
+// Tell the renderer process that an audio stream has been created.
+// The renderer process is given a shared memory handle for the audio data
+// buffer it shares with the browser process. It is also given a SyncSocket that
+// it uses to communicate with the browser process about the state of the
+// buffered audio data.
 #if defined(OS_WIN)
-IPC_MESSAGE_CONTROL4(AudioMsg_NotifyLowLatencyStreamCreated,
+IPC_MESSAGE_CONTROL4(AudioMsg_NotifyStreamCreated,
                      int /* stream id */,
                      base::SharedMemoryHandle /* handle */,
                      base::SyncSocket::Handle /* socket handle */,
                      uint32 /* length */)
 #else
-IPC_MESSAGE_CONTROL4(AudioMsg_NotifyLowLatencyStreamCreated,
+IPC_MESSAGE_CONTROL4(AudioMsg_NotifyStreamCreated,
                      int /* stream id */,
                      base::SharedMemoryHandle /* handle */,
                      base::FileDescriptor /* socket handle */,
                      uint32 /* length */)
 #endif
 
 // Tell the renderer process that a low latency audio input stream has been
 // created, renderer process would be given a SyncSocket that it should read
 // from from then on.
 #if defined(OS_WIN)
@@ skipping 14 matching lines @@
 // update after the renderer has requested a Create/Start/Close.
 IPC_MESSAGE_CONTROL2(AudioMsg_NotifyStreamStateChanged,
                      int /* stream id */,
                      AudioStreamState /* new state */)
 
 // Notification message sent from browser to renderer for state update.
 IPC_MESSAGE_CONTROL2(AudioInputMsg_NotifyStreamStateChanged,
                      int /* stream id */,
                      AudioStreamState /* new state */)
 
-IPC_MESSAGE_CONTROL2(AudioMsg_NotifyStreamVolume,
-                     int /* stream id */,
-                     double /* volume */)
-
 IPC_MESSAGE_CONTROL2(AudioInputMsg_NotifyStreamVolume,
                      int /* stream id */,
                      double /* volume */)
 
 IPC_MESSAGE_CONTROL2(AudioInputMsg_NotifyDeviceStarted,
                      int /* stream id */,
                      std::string /* device_id */)
 
 // Messages sent from the renderer to the browser.
 
 // Request that got sent to browser for creating an audio output stream
-IPC_MESSAGE_CONTROL3(AudioHostMsg_CreateStream,
+IPC_MESSAGE_CONTROL2(AudioHostMsg_CreateStream,
                      int /* stream_id */,
-                     AudioParameters /* params */,
-                     bool /* low-latency */)
+                     AudioParameters /* params */)
 
 // Request that got sent to browser for creating an audio input stream
 IPC_MESSAGE_CONTROL4(AudioInputHostMsg_CreateStream,
                      int /* stream_id */,
                      AudioParameters /* params */,
                      bool /* low-latency */,
                      std::string /* device_id */)
 
-// Tell the browser the audio buffer prepared for stream (stream_id) is
-// filled and is ready to be consumed.
-IPC_MESSAGE_CONTROL2(AudioHostMsg_NotifyPacketReady,
-                     int /* stream_id */,
-                     uint32 /* packet size */)
-
 // Start buffering and play the audio stream specified by stream_id.
 IPC_MESSAGE_CONTROL1(AudioHostMsg_PlayStream,
                      int /* stream_id */)
 
 // Start recording the audio input stream specified by stream_id.
 IPC_MESSAGE_CONTROL1(AudioInputHostMsg_RecordStream,
                      int /* stream_id */)
 
 // Pause the audio stream specified by stream_id.
 IPC_MESSAGE_CONTROL1(AudioHostMsg_PauseStream,
                      int /* stream_id */)
 
 // Discard all buffered audio data for the specified audio stream.
 IPC_MESSAGE_CONTROL1(AudioHostMsg_FlushStream,
                      int /* stream_id */)
 
 // Close an audio stream specified by stream_id.
 IPC_MESSAGE_CONTROL1(AudioHostMsg_CloseStream,
                      int /* stream_id */)
 
 // Close an audio input stream specified by stream_id.
 IPC_MESSAGE_CONTROL1(AudioInputHostMsg_CloseStream,
                      int /* stream_id */)
 
-// Get audio volume of the stream specified by stream_id.
-IPC_MESSAGE_CONTROL1(AudioHostMsg_GetVolume,
-                     int /* stream_id */)
-
 // Get audio volume of the input stream specified by
 // (render_view_id, stream_id).
 IPC_MESSAGE_CONTROL1(AudioInputHostMsg_GetVolume,
                      int /* stream_id */)
 
 // Set audio volume of the stream specified by stream_id.
 // TODO(hclam): change this to vector if we have channel numbers other than 2.
 IPC_MESSAGE_CONTROL2(AudioHostMsg_SetVolume,
                      int /* stream_id */,
                      double /* volume */)
 
 // Set audio volume of the input stream specified by stream_id.
 IPC_MESSAGE_CONTROL2(AudioInputHostMsg_SetVolume,
                      int /* stream_id */,
                      double /* volume */)
 
 // Start the device referenced by the session_id for the input stream specified
 // by stream_id.
 IPC_MESSAGE_CONTROL2(AudioInputHostMsg_StartDevice,
                      int /* stream_id */,
                      int /* session_id */)