[skottie] Initial animated text properties support

Limitations:

  - no range selectors (applies to the whole text)
  - only position, fill color and stroke color for now

Change-Id: I91e88a6107c5f66687c1c27f27a71be3914bde25
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/217386
Commit-Queue: Florin Malita <fmalita@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
diff --git a/modules/skottie/skottie.gni b/modules/skottie/skottie.gni
index 1b64d66..6a1488e 100644
--- a/modules/skottie/skottie.gni
+++ b/modules/skottie/skottie.gni
@@ -32,6 +32,8 @@
   "$_src/text/SkottieShaper.h",
   "$_src/text/TextAdapter.cpp",
   "$_src/text/TextAdapter.h",
+  "$_src/text/TextAnimator.cpp",
+  "$_src/text/TextAnimator.h",
   "$_src/text/TextLayer.cpp",
   "$_src/text/TextValue.cpp",
   "$_src/text/TextValue.h",