[skottie] Clean up SkottieProperties

Split into Adapter and Value CUs.

No real changes, just shuffling things around.

TBR=
Change-Id: I50eaeb3950f4c59e7d7027955b3f49ca2a346e59
Reviewed-on: https://skia-review.googlesource.com/116186
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Florin Malita <fmalita@chromium.org>
diff --git a/BUILD.gn b/BUILD.gn
index cc7468f..ff99776 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1357,9 +1357,10 @@
     include_dirs = [ "tools" ]
     sources = [
       "experimental/skottie/Skottie.cpp",
+      "experimental/skottie/SkottieAdapter.cpp",
       "experimental/skottie/SkottieAnimator.cpp",
       "experimental/skottie/SkottieParser.cpp",
-      "experimental/skottie/SkottieProperties.cpp",
+      "experimental/skottie/SkottieValue.cpp",
     ]
     deps = [
       ":experimental_sksg",