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

content/public/browser/desktop_media_id.cc

Index: content/public/browser/desktop_media_id.cc
diff --git a/content/public/browser/desktop_media_id.cc b/content/public/browser/desktop_media_id.cc
index 8a20598af67f82db03a1dffad8601597df05d1c3..6c0027d40ad65bfdaf8f646d5a849ab1328834e4 100644
--- a/content/public/browser/desktop_media_id.cc
+++ b/content/public/browser/desktop_media_id.cc
@@ -129,8 +129,8 @@ bool DesktopMediaID::operator==(const DesktopMediaID& other) const {
 //                         window:"window_id:aura_id".
 DesktopMediaID DesktopMediaID::Parse(const std::string& str) {
   // For WebContents type.
-  WebContentsMediaCaptureId web_id = WebContentsMediaCaptureId::Parse(str);
-  if (!web_id.is_null())
+  WebContentsMediaCaptureId web_id;
+  if (WebContentsMediaCaptureId::Parse(str, &web_id))
     return DesktopMediaID(TYPE_WEB_CONTENTS, 0, web_id);
 
   // For screen and window types.