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

content/renderer/media/user_media_client_impl.cc

Index: content/renderer/media/user_media_client_impl.cc
diff --git a/content/renderer/media/user_media_client_impl.cc b/content/renderer/media/user_media_client_impl.cc
index bda19f7a6c3e87554a2b1f3cea2f253b38287e39..2518da1bb73686e6896febcca94449813190af3b 100644
--- a/content/renderer/media/user_media_client_impl.cc
+++ b/content/renderer/media/user_media_client_impl.cc
@@ -85,6 +85,17 @@ void CopyBlinkRequestToStreamControls(const blink::WebUserMediaRequest& request,
         }
       }
     }
+
+    bool exact = request.audioConstraints().basic().muteSourceAudio.exact();
+    bool has_exact =
+        request.audioConstraints().basic().muteSourceAudio.hasExact();
+
+    if (has_exact) {
+      controls->mute_source_audio = exact;
+    } else {
+      controls->mute_source_audio =
+          controls->audio.stream_source != kMediaStreamSourceDesktop;
+    }
   }
   if (!request.videoConstraints().isNull()) {
     const blink::WebMediaTrackConstraintSet& video_basic =