Bug 1328061 - Restore dragging state when video seeks to the same point twice. r=Gijs

MozReview-Commit-ID: 2AiMzufcKyd

--HG--
extra : rebase_source : 790325cbf5b7c676c11f00cdf32195ebe61e33b0

toolkit/content/widgets/videocontrols.xml

@@ -1745,6 +1745,9 @@
         if (!this.videocontrols.isTouchControls) {
           addListener(this.scrubber, "input", this.onScrubberInput);
           addListener(this.scrubber, "change", this.onScrubberChange);
+          // add mouseup listener additionally to handle the case that `change` event
+          // isn't fired when the input value before/after dragging are the same. (bug 1328061)
+          addListener(this.scrubber, "mouseup", this.onScrubberChange);
           addListener(this.volumeControl, "input", this.updateVolume);
           addListener(this.video.textTracks, "addtrack", this.onTextTrackAdd);
           addListener(this.video.textTracks, "removetrack", this.onTextTrackRemove);