Add animated text samples

BUG=skia:

Change-Id: I0b0a00a0d5c5790a1fc963458bc90c968830afd8
Reviewed-on: https://skia-review.googlesource.com/8361
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Mike Reed <reed@google.com>
2 files changed