Bug 1213154 - tab-sound-icon should be supported by bfcache, r=roc

--HG--
extra : rebase_source : c75b227254aa5701eb728afef09a803e2698e600

dom/html/HTMLMediaElement.cpp

@@ -4727,6 +4727,12 @@ HTMLMediaElement::IsPlayingThroughTheAudioChannel() const
     return false;
   }
 
+  // We should consider any bfcached page or inactive document/channel as
+  // non-playing.
+  if (mPausedForInactiveDocumentOrChannel) {
+    return false;
+  }
+
   // A loop always is playing
   if (HasAttr(kNameSpaceID_None, nsGkAtoms::loop)) {
     return true;