Move ui/gfx/animation/ into its own component.

ui/gfx/animation/BUILD.gn

+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import("//build/config/ui.gni")
+
+if (is_android) {
+  import("//build/config/android/config.gni")
+  import("//build/config/android/rules.gni")
+}
+
+component("animation") {
+  sources = [
+    "animation.cc",
+    "animation.h",
+    "animation_container.cc",
+    "animation_container.h",
+    "animation_container_element.h",
+    "animation_container_observer.h",
+    "animation_delegate.h",
+    "animation_export.h",
+    "animation_mac.mm",
+    "animation_win.cc",
+    "linear_animation.cc",
+    "linear_animation.h",
+    "multi_animation.cc",
+    "multi_animation.h",
+    "slide_animation.cc",
+    "slide_animation.h",
+    "throb_animation.cc",
+    "throb_animation.h",
+    "tween.cc",
+    "tween.h",
+  ]
+
+  # Android.

[sky, 2017/03/14 23:53:08]

Remove this comment as it's obvious given the next line (you don't have the same
comment on line 7).

[chrishtr, 2017/03/15 03:26:36]

Done.

+  if (is_android) {
+    if (!use_aura) {
+      sources -= [
+        "throb_animation.cc",
+        "throb_animation.h",
+      ]
+    }
+  }
+
+  deps = [
+    "//base",
+    "//skia",
+    "//ui/gfx:geometry_skia",
+    "//ui/gfx:gfx_export",
+    "//ui/gfx/geometry",
+  ]
+  defines = [ "ANIMATION_IMPLEMENTATION" ]
+}