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

content/renderer/media/audio_hardware.cc

 // 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.
 
 #include "content/renderer/media/audio_hardware.h"
 
 #include "base/logging.h"
 #include "content/common/view_messages.h"
 #include "content/renderer/render_thread_impl.h"
 
 static double output_sample_rate = 0.0;
 static double input_sample_rate = 0.0;
 static size_t output_buffer_size = 0;
+static uint32 input_channel_count = 0;
 
 namespace audio_hardware {
 
 double GetOutputSampleRate() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   if (!output_sample_rate) {
     RenderThreadImpl::current()->Send(
         new ViewHostMsg_GetHardwareSampleRate(&output_sample_rate));
   }
@@ skipping 16 matching lines @@
   if (!output_buffer_size) {
     uint32 buffer_size = 0;
     RenderThreadImpl::current()->Send(
         new ViewHostMsg_GetHardwareBufferSize(&buffer_size));
     output_buffer_size = buffer_size;
   }
 
   return output_buffer_size;
 }
 
+uint32 GetInputChannelCount() {
+  DCHECK(RenderThreadImpl::current() != NULL);
+
+  if (!input_channel_count) {
+    uint32 channels = 0;
+    RenderThreadImpl::current()->Send(
+        new ViewHostMsg_GetHardwareInputChannelCount(&channels));
+    input_channel_count = channels;
+  }
+
+  return input_channel_count;
+}
+
 void ResetCache() {
   DCHECK(RenderThreadImpl::current() != NULL);
 
   output_sample_rate = 0.0;
   input_sample_rate = 0.0;
   output_buffer_size = 0;
+  input_channel_count = 0;
 }
 
 }  // namespace audio_hardware