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..2bf9f4c12ba54aaa666de732ff6efac52150b99f 100644
--- a/third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp
+++ b/third_party/WebKit/Source/modules/mediastream/MediaConstraintsImpl.cpp
@@ -91,6 +91,7 @@ const char kMediaStreamAudioHotword[] = "googHotword";
 // TODO(hta): googHotword should go away. https://crbug.com/577627
 // From content/renderer/media/media_stream_audio_processor_options.cc
 const char kEchoCancellation[] = "echoCancellation";
+const char kDisableLocalEcho[] = "disableLocalEcho";
 const char kGoogEchoCancellation[] = "googEchoCancellation";
 const char kGoogExperimentalEchoCancellation[] = "googEchoCancellation2";
 const char kGoogAutoGainControl[] = "googAutoGainControl";
@@ -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(kDisableLocalEcho) && RuntimeEnabledFeatures::desktopCaptureDisableLocalEchoControlEnabled()) {
+            result.disableLocalEcho.setExact(toBoolean(constraint.m_value));
         } else if (constraint.m_name.equals(kMediaStreamSourceId)
             || constraint.m_name.equals(kMediaStreamSourceInfoId)) {
             result.deviceId.setExact(constraint.m_value);