Bug 1659941 - Avoid an IntervalSet copy when inserting frames in TrackBuffersManager. r=jya

Differential Revision: https://phabricator.services.mozilla.com/D87913

dom/media/mediasource/TrackBuffersManager.cpp

@@ -2080,10 +2080,7 @@ void TrackBuffersManager::InsertFrames(TrackBuffer& aSamples,
   // the previous step and the next random access point after those removed
   // frames.
 
-  TimeIntervals intersection = trackBuffer.mBufferedRanges;
-  intersection.Intersection(aIntervals);
-
-  if (!intersection.IsEmpty()) {
+  if (trackBuffer.mBufferedRanges.IntersectsStrict(aIntervals)) {
     if (aSamples[0]->mKeyframe &&
         (mType.Type() == MEDIAMIMETYPE("video/webm") ||
          mType.Type() == MEDIAMIMETYPE("audio/webm"))) {