MediaStream audio: Refactor 3 separate "glue" implementations into one.

content/renderer/media/mock_media_stream_dispatcher.cc

Index: content/renderer/media/mock_media_stream_dispatcher.cc
diff --git a/content/renderer/media/mock_media_stream_dispatcher.cc b/content/renderer/media/mock_media_stream_dispatcher.cc
index b173192e8894a03a5e2cf91a876c35be88d30b46..86947d0b7d2a4ea8fd9d6b9dd92eb4b393e5340d 100644
--- a/content/renderer/media/mock_media_stream_dispatcher.cc
+++ b/content/renderer/media/mock_media_stream_dispatcher.cc
@@ -6,6 +6,7 @@
 
 #include "base/strings/string_number_conversions.h"
 #include "content/public/common/media_stream_request.h"
+#include "media/base/audio_parameters.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 // Used for ID for output devices and for matching output device ID for input
@@ -117,6 +118,9 @@ void MockMediaStreamDispatcher::AddAudioInputDeviceToArray(
         kAudioOutputDeviceIdPrefix + base::IntToString(session_id_);
   }
   audio.session_id = session_id_;
+  audio.device.input.sample_rate = media::AudioParameters::kAudioCDSampleRate;
+  audio.device.input.channel_layout = media::CHANNEL_LAYOUT_STEREO;
+  audio.device.input.frames_per_buffer = audio.device.input.sample_rate / 100;
   audio_input_array_.push_back(audio);
 }