Rename AnimationPlayer to Animation in cc and all its clients

This patch updates the name cc::AnimationPlayer to cc::Animation so that
it will be consistent with the blink::Animation. It's a follow-up patch
of https://chromium-review.googlesource.com/c/chromium/src/+/906830.

Other clients of cc::Animation (vr, ui) have been updated accordingly.

Bug: 807667
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_vr;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: If80affe7bedf46ae8f0356a6fa8a89e2f1d81973
Reviewed-on: https://chromium-review.googlesource.com/926901
Reviewed-by: Stephen McGruer <[email protected]>
Reviewed-by: Majid Valipour <[email protected]>
Reviewed-by: Ian Vollick <[email protected]>
Reviewed-by: Robert Flack <[email protected]>
Commit-Queue: Yi Gu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#538327}
96 files changed