This is in anticipation of adding Animation::SetTimeline(). Once we set the
timeline out of band, there's a chance that getting it could return null so
this patch makes the WebIDL and method name reflect that.
--HG--
extra : commitid : FSiwvrGRV1v
extra : rebase_source : 4c4004f58bbfd340642277b0a0b547a7de692dac
This is needed not only for supporting other kinds of timelines, but also for
when we come to implement SetTimeline(AnimationTimeline* aTimeline).
--HG--
extra : commitid : B836jCSbgNL
extra : rebase_source : 2592e66b2a9009f85ec0189ebecf5dba3c9bf8e0
This is not strictly necessary yet but we will want to implement methods
like GetAnimations() on the base class, AnimationTimeline, so we may as well do
that now rather than adding that code to DocumentTimeline and moving it later.
--HG--
extra : commitid : 7GU6Dr9lnPO
extra : rebase_source : d5e788874c72c422b57efbdb81404c79df6d505b
This patch also updates the method names on PendingAnimationTracker but leaves
a number of local variables which will be fixed in a subsequent patch.
--HG--
rename : dom/animation/PendingPlayerTracker.cpp => dom/animation/PendingAnimationTracker.cpp
rename : dom/animation/PendingPlayerTracker.h => dom/animation/PendingAnimationTracker.h
