Fix bug in Synchronizer that caused throttling to fail, resulting in excessive memory usage.

The seemingly harmless PTS adjustment of slightly-too-early frames caused
frames to be added after the predicted segment end. Since delays inserted
as a result of throttling are never inserted after the predicted segment
end, no delays were inserted at all and throttling never happened.
New version.
Add missing newline.
Merge branch 'master' into glinject-next