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

content/test/BUILD.gn

Index: content/test/BUILD.gn
diff --git a/content/test/BUILD.gn b/content/test/BUILD.gn
index 051aaac408a0cb5306c9a741336d15b28978d4e0..7c7f6e90df7ef7cbb252cd1773068d695bcad029 100644
--- a/content/test/BUILD.gn
+++ b/content/test/BUILD.gn
@@ -214,6 +214,7 @@ static_library("test_support") {
     ":content_test_mojo_bindings",
     "//base/third_party/dynamic_annotations",
     "//cc:test_support",
+    "//cc/animation",
     "//cc/blink",
     "//cc/ipc",
     "//cc/surfaces",
@@ -405,6 +406,7 @@ static_library("browsertest_support") {
     "//base:i18n",
     "//base/test:test_config",
     "//base/test:test_support",
+    "//cc/animation",
     "//cc/surfaces",
     "//content/app:both_for_content_tests",
     "//content/browser:for_content_tests",
@@ -1363,6 +1365,7 @@ test("content_unittests") {
     "//base/third_party/dynamic_annotations",
     "//cc",
     "//cc:test_support",
+    "//cc/animation",
     "//cc/ipc",
     "//cc/surfaces",
     "//components/display_compositor",