Move ui/gfx/animation/ into its own component.

This is necessary to break an include cycle between cc and ui/gfx/ for upcoming
changes to cc/paint/.

BUG=665259
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2750743003
Cr-Commit-Position: refs/heads/master@{#457084}
18 files changed