Tweak the TextTrackCue "cue index" management

Source/core/html/track/CueTimeline.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "core/html/track/CueTimeline.h"
 
 #include "core/events/Event.h"
 #include "core/html/HTMLMediaElement.h"
 #include "core/html/HTMLTrackElement.h"
@@ skipping 77 matching lines @@
 
     // If the cues belong to different text tracks, it doesn't make sense to
     // compare the two tracks by the relative cue order, so return the relative
     // track order.
     if (a.second->track() != b.second->track())
         return trackIndexCompare(a.second->track(), b.second->track());
 
     // 12 - Further sort tasks in events that have the same time by the
     // relative text track cue order of the text track cues associated
     // with these tasks.
-    return a.second->cueIndex() - b.second->cueIndex() < 0;
+    return a.second->cueIndex() < b.second->cueIndex();
 }
 
 static PassRefPtrWillBeRawPtr<Event> createEventWithTarget(const AtomicString& eventName, PassRefPtrWillBeRawPtr<EventTarget> eventTarget)
 {
     RefPtrWillBeRawPtr<Event> event = Event::create(eventName);
     event->setTarget(eventTarget);
     return event.release();
 }
 
 void CueTimeline::updateActiveCues(double movieTime)
@@ skipping 223 matching lines @@
     if (!m_ignoreUpdate && mediaElement().inActiveDocument())
         updateActiveCues(mediaElement().currentTime());
 }
 
 DEFINE_TRACE(CueTimeline)
 {
     visitor->trace(m_mediaElement);
 }
 
 } // namespace blink