Bug 1344357 P3 - dont' pass dom::Promise into MediaDecoder anymore; r=jwwang

MozReview-Commit-ID: 5RUNauRRajP

dom/html/HTMLMediaElement.cpp

@@ -2724,7 +2724,7 @@ HTMLMediaElement::Seek(double aTime,
   // The media backend is responsible for dispatching the timeupdate
   // event if it changes the playback position as a result of the seek.
   LOG(LogLevel::Debug, ("%p SetCurrentTime(%f) starting seek", this, aTime));
-  nsresult rv = mDecoder->Seek(aTime, aSeekType, promise);
+  nsresult rv = mDecoder->Seek(aTime, aSeekType);
   if (NS_FAILED(rv)) {
     aRv.Throw(rv);
     return nullptr;