Baby steps towards an odeon-like animation system. First victim: Drawer.

sky/sdk/BUILD.gn

 # Copyright 2015 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("//mojo/public/dart/rules.gni")
 
 dart_pkg("sdk") {
   sources = [
     "CHANGELOG.md",
     "bin/init.dart",
     "lib/animation/animated_value.dart",
+    "lib/animation/animation_performance.dart",
     "lib/animation/curves.dart",
     "lib/animation/fling_curve.dart",
     "lib/animation/generators.dart",
     "lib/animation/mechanics.dart",
     "lib/animation/scroll_behavior.dart",
     "lib/assets/.gitignore",
     "lib/assets/material-design-icons.sha1",
     "lib/base/debug.dart",
     "lib/base/hit_test.dart",
+    "lib/base/lerp.dart",
     "lib/base/node.dart",
     "lib/base/scheduler.dart",
     "lib/download_material_design_icons",
     "lib/editing/editable_string.dart",
     "lib/editing/editable_text.dart",
     "lib/editing/input.dart",
     "lib/editing/keyboard.dart",
     "lib/framework/animation/animated_value.dart",
     "lib/framework/animation/curves.dart",
     "lib/framework/animation/fling_curve.dart",
@@ skipping 106 matching lines @@
     "//mojo/dart/mojo_services",
     "//mojo/dart/mojom",
     "//mojo/public/dart:mojo",
     "//sky/engine/bindings",
     "//sky/services/testing",
     "//third_party/dart-pkg",
   ]
 
   sdk_ext_directory = "$root_gen_dir/sky/bindings"
 }