--- a/dom/locales/en-US/chrome/dom/dom.properties
+++ b/dom/locales/en-US/chrome/dom/dom.properties
@@ -97,16 +97,18 @@ MediaDecodeAudioDataUnknownError=An unkn
 # LOCALIZATION NOTE: Do not translate decodeAudioData.
 MediaDecodeAudioDataInvalidContent=The buffer passed to decodeAudioData contains invalid content which cannot be decoded successfully.
 # LOCALIZATION NOTE: Do not translate decodeAudioData.
 MediaDecodeAudioDataNoAudio=The buffer passed to decodeAudioData does not contain any audio.
 # LOCALIZATION NOTE: Do not translate HTMLMediaElement and createMediaElementSource.
 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.
 # LOCALIZATION NOTE: %1$S is the Http error code the server returned (e.g. 404, 500, etc), %2$S is the URL of the media resource which failed to load.
 MediaLoadHttpError=HTTP load failed with status %1$S. Load of media resource %2$S failed.
 # LOCALIZATION NOTE: %S is the URL of the media resource which failed to load.
 MediaLoadInvalidURI=Invalid URI. Load of media resource %S failed.
 # LOCALIZATION NOTE: %1$S is the media resource's format/codec type (basically equivalent to the file type, e.g. MP4,AVI,WMV,MOV etc), %2$S is the URL of the media resource which failed to load.