Adds support for 16kHz input sample rate and mono channel config. in WebRTC.

content/common/view_messages.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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/common/content_export.h"
@@ skipping 674 matching lines @@
                             uint32 /* buffer_size */)
 
 // Asks the browser for the default audio input hardware sample-rate.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareInputSampleRate,
                             double /* sample_rate */)
 
 // Asks the browser for the default audio hardware sample-rate.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareSampleRate,
                             double /* sample_rate */)
 
+// Asks the browser for the default number of audio input channels.
+IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetHardwareInputChannelCount,
+                            size_t /* channels */)

[jam, 2012/01/18 18:44:38]

we avoid size_t in IPC messages by convention, because we do have 32/64 bit
processes taking to each other. while that doesn't happen for browser<>renderer,
it's easier to just say avoid size_t in all IPCs since sometimes it's not clear
which channels an IPC goes over

[henrika (OOO until Aug 14), 2012/01/19 09:42:24]

I will change to int instead.

+
 // Asks the browser for CPU usage of the renderer process in percents.
 IPC_SYNC_MESSAGE_CONTROL0_1(ViewHostMsg_GetCPUUsage,
                             int /* CPU usage in percents */)
 
 // Tells the renderer to create a new view.
 // This message is slightly different, the view it takes (via
 // ViewMsg_New_Params) is the view to create, the message itself is sent as a
 // non-view control message.
 IPC_MESSAGE_CONTROL1(ViewMsg_New,
                      ViewMsg_New_Params)
@@ skipping 1270 matching lines @@
                      media::MediaLogEvent /* event */)
 
 // Requests to lock the mouse. Will result in a ViewMsg_LockMouse_ACK message
 // being sent back.
 IPC_MESSAGE_ROUTED0(ViewHostMsg_LockMouse)
 
 // Requests to unlock the mouse. A ViewMsg_MouseLockLost message will be sent
 // whenever the mouse is unlocked (which may or may not be caused by
 // ViewHostMsg_UnlockMouse).
 IPC_MESSAGE_ROUTED0(ViewHostMsg_UnlockMouse)