Bug 1457361 - Add the missing error string for MediaElementAudioSourceNode with MediaStream. r=jib

MozReview-Commit-ID: HXiN1RQVHJ0

--HG--
extra : rebase_source : 2d5efb55cbfa5ba26ae2598aa8aa1dcc75e0272c

dom/locales/en-US/chrome/dom/dom.properties

@@ -102,6 +102,8 @@ MediaDecodeAudioDataNoAudio=The buffer passed to decodeAudioData does not contai
 MediaElementAudioSourceNodeCrossOrigin=The HTMLMediaElement passed to createMediaElementSource has a cross-origin resource, the node will output silence.
 # LOCALIZATION NOTE: Do not translate MediaStream and createMediaStreamSource.
 MediaStreamAudioSourceNodeCrossOrigin=The MediaStream passed to createMediaStreamSource has a cross-origin resource, the node will output silence.
+# LOCALIZATION NOTE: Do not translate HTMLMediaElement and MediaStream.
+MediaElementAudioCaptureOfMediaStreamError=The captured HTMLMediaElement is playing a MediaStream. Applying volume or mute status is not currently supported.
 MediaLoadExhaustedCandidates=All candidate resources failed to load. Media load paused.
 MediaLoadSourceMissingSrc=<source> element has no “src” attribute. Media resource load failed.
 MediaStreamAudioSourceNodeDifferentRate=Connecting AudioNodes from AudioContexts with different sample-rate is currently not supported.