Devtools Animations: Add buffer and effect selection to animation timeline

This change allows the animation timeline UI to consume the visual effect
information from the backend models. It pulls these effects into a buffer
and allows each effect to be selected to be displayed in the timeline below.
The scrubber is also disabled for now in this change.


Review URL:

git-svn-id: svn:// bbb929c8-8fbe-4397-9dbb-9b2b20218538
8 files changed