CC Animation: Make cc/animation an independent GN component.

ui/compositor/BUILD.gn

Index: ui/compositor/BUILD.gn
diff --git a/ui/compositor/BUILD.gn b/ui/compositor/BUILD.gn
index e044473da51a216809d2949fe3a6bdd2e5338060..50abe0bb83181f2078ebd1af4b5d2150e67691ff 100644
--- a/ui/compositor/BUILD.gn
+++ b/ui/compositor/BUILD.gn
@@ -78,6 +78,7 @@ component("compositor") {
     "//base",
     "//base/third_party/dynamic_annotations",
     "//cc",
+    "//cc/animation",
     "//cc/surfaces",
     "//cc/surfaces:surface_id",
     "//gpu/command_buffer/common",
@@ -139,6 +140,7 @@ static_library("test_support") {
     "//base/test:test_support",
     "//cc",
     "//cc:test_support",
+    "//cc/animation",
     "//cc/surfaces",
     "//gpu/command_buffer/client:gles2_c_lib",
     "//gpu/command_buffer/client:gles2_implementation",
@@ -190,6 +192,7 @@ test("compositor_unittests") {
     "//base/test:test_support",
     "//cc",
     "//cc:test_support",
+    "//cc/animation",
     "//cc/surfaces",
     "//cc/surfaces:surface_id",
     "//skia",