Bug 1513039 - part14 : add new error message for web audio. r=baku,flod

Differential Revision: https://phabricator.services.mozilla.com/D14637

--HG--
extra : moz-landing-system : lando

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

@@ -150,6 +150,7 @@ MediaEMENoCodecsDeprecatedWarning=Calling navigator.requestMediaKeySystemAccess(
 # LOCALIZATION NOTE: Do not translate "Mutation Event" and "MutationObserver"
 MutationEventWarning=Use of Mutation Events is deprecated. Use MutationObserver instead.
 BlockAutoplayError=Autoplay is only allowed when approved by the user, the site is activated by the user, or media is muted.
+BlockAutoplayWebAudioError=Autoplay is only allowed after site is activated by the user gestures, or AudioContext is offline.
 # LOCALIZATION NOTE: Do not translate "Components"
 ComponentsWarning=The Components object is deprecated. It will soon be removed.
 PluginHangUITitle=Warning: Unresponsive plugin

dom/media/webaudio/AudioContext.cpp

@@ -967,7 +967,7 @@ void AudioContext::ResumeInternal() {
 }
 
 void AudioContext::ReportBlocked() {
-  ReportToConsole(nsIScriptError::warningFlag, "BlockAutoplayError");
+  ReportToConsole(nsIScriptError::warningFlag, "BlockAutoplayWebAudioError");
   mWasAllowedToStart = false;
 
   if (!StaticPrefs::MediaBlockEventEnabled()) {