Don't use absolute bounding boxes in LayoutVTTCue
LayoutVTTCue was using absoluteContentBox()/absoluteBoundingBoxRect()
during overlap resolution. This would mean that boxes were computed
relative to the containing frame. The former also doesn't take
transforms into account, which would mean that the basic overlap check
against the title area would fail if a transform was present.
Instead compute the various bounding boxes relative to a common
ancestor, namely the text track container (which is also the containing
block of the cues.) Adjust the controls rect similarly to get it into the
same coordinate space.
BUG=647253
Review-Url: https://codereview.chromium.org/2377193003
Cr-Commit-Position: refs/heads/master@{#422072}
4 files changed
