Let Contraints Controll Mute/Unmute Audio Local Playback For Desktop Sharing

third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp

Index: third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp
diff --git a/third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp b/third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp
index 56c542d99bb0fa2d43524cb05623ef93976c2a78..ed30721e21f5a648f7fdee5b07348e6c9ecd7b02 100644
--- a/third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp
+++ b/third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp
@@ -83,6 +83,7 @@ const char kMaxFrameRate[] = "maxFrameRate";
 const char kMinFrameRate[] = "minFrameRate";
 // From content/common/media/media_stream_options.cc
 const char kMediaStreamSource[] = "chromeMediaSource";
+const char kMuteSourceAudio[] = "muteSourceAudio";
 const char kMediaStreamSourceId[] = "chromeMediaSourceId"; // mapped to deviceId
 const char kMediaStreamSourceInfoId[] = "sourceId"; // mapped to deviceId
 const char kMediaStreamRenderToAssociatedSink[] = "chromeRenderToAssociatedSink";
@@ -294,6 +295,8 @@ static void parseOldStyleNames(ExecutionContext* context, const Vector<NameValue
             // represented as an enum, and cause type errors.
             // https://crbug.com/576582
             result.mediaStreamSource.setExact(constraint.m_value);
+        } else if (constraint.m_name.equals(kMuteSourceAudio)) {
+            result.muteSourceAudio.setExact(toBoolean(constraint.m_value));
         } else if (constraint.m_name.equals(kMediaStreamSourceId)
             || constraint.m_name.equals(kMediaStreamSourceInfoId)) {
             result.deviceId.setExact(constraint.m_value);