Support 3 channels for audio input.

Test code in https://codereview.chromium.org/255753003/

BUG=345296

Review URL: https://codereview.chromium.org/197453002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266849 0039d316-1c4b-4281-b951-d872f2087c98

content/renderer/media/webrtc_audio_capturer.cc

@@ -173,7 +173,8 @@ bool WebRtcAudioCapturer::Initialize() {
 
   // Verify that the reported input channel configuration is supported.
   if (channel_layout != media::CHANNEL_LAYOUT_MONO &&
-      channel_layout != media::CHANNEL_LAYOUT_STEREO) {
+      channel_layout != media::CHANNEL_LAYOUT_STEREO &&
+      channel_layout != media::CHANNEL_LAYOUT_STEREO_AND_KEYBOARD_MIC) {
     DLOG(ERROR) << channel_layout
                 << " is not a supported input channel configuration.";
     return false;

media/audio/audio_input_controller.cc

@@ -11,7 +11,7 @@
 #include "media/base/user_input_monitor.h"
 
 namespace {
-const int kMaxInputChannels = 2;
+const int kMaxInputChannels = 3;
 
 // TODO(henrika): remove usage of timers and add support for proper
 // notification of when the input device is removed.  This was originally added

media/audio/audio_manager_base.cc

@@ -28,7 +28,7 @@ static const int kDefaultMaxOutputStreams = 16;
 // for all platforms.
 static const int kDefaultMaxInputStreams = 16;
 
-static const int kMaxInputChannels = 2;
+static const int kMaxInputChannels = 3;
 
 const char AudioManagerBase::kDefaultDeviceName[] = "Default";
 const char AudioManagerBase::kDefaultDeviceId[] = "default";