Move Material Design Icons to their own package

After this patch, we use pub to manage versioning and fetching the material
design icons.

packages/flutter/BUILD.gn

@@ -15,14 +15,11 @@ dart_pkg("sky") {
     "lib/animation/forces.dart",
     "lib/animation/scroll_behavior.dart",
     "lib/animation/timeline.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",
@@ -115,34 +112,8 @@ dart_pkg("sky") {
   ]
 }
 
-action("material_design_icons") {
-  source_file = "lib/assets/material-design-icons"
-  target_file = "$root_gen_dir/dart-pkg/sky/lib/assets/material-design-icons"
-  stamp = "$target_gen_dir/material_design_icons_linked"
-
-  sources = [
-    "lib/assets/material-design-icons.sha1",
-  ]
-  outputs = [
-    stamp,
-  ]
-
-  script = "//sky/build/symlink.py"
-  args = [
-    rebase_path(source_file, root_build_dir),
-    rebase_path(target_file, root_build_dir),
-    "--touch",
-    rebase_path(stamp, root_build_dir),
-  ]
-
-  deps = [
-    ":sky",
-  ]
-}
-
 group("sdk") {
   deps = [
     ":sky",
-    ":material_design_icons",
   ]
 }

packages/flutter/lib/assets/.gitignore

-material-design-icons

packages/flutter/lib/assets/material-design-icons.sha1

-74927f91069e6540e40983acb5eb40072704fd2f

packages/flutter/lib/download_material_design_icons

-#!/usr/bin/env python
-# Copyright (c) 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 os
-import shutil
-import subprocess
-import sys
-import urllib2
-
-
-def main():
-    sky_lib_dir = os.path.dirname(os.path.abspath(__file__))
-    assets_dir = os.path.join(sky_lib_dir, 'assets')
-    icons_dir = os.path.join(assets_dir, 'material-design-icons')
-    existing_sha1_path = os.path.join(icons_dir, 'material-design-icons.sha1')
-
-    existing_sha1 = None
-    if os.path.isfile(existing_sha1_path):
-        with open(existing_sha1_path, 'r') as f:
-            existing_sha1 = f.read()
-
-    sha1_path = os.path.join(assets_dir, 'material-design-icons.sha1')
-
-    with open(sha1_path, 'r') as f:
-        sha1 = f.read()
-
-    if existing_sha1 == sha1:
-        return
-
-    print "Downloading missing material design icons"
-
-    tgz_path = os.path.join(assets_dir, 'material-design-icons.tgz')
-    url = 'https://storage.googleapis.com/mojo/material-design-icons/%s' % sha1
-    response = urllib2.urlopen(url)
-
-    with open(tgz_path, 'wb') as f:
-        f.write(response.read())
-
-    shutil.rmtree(icons_dir, ignore_errors=True)
-
-    output_path = os.path.join(assets_dir, tgz_path)
-    subprocess.call([
-        'tar', '-xzf', output_path, '-C', assets_dir
-    ])
-
-    subprocess.call([
-        'cp', sha1_path, icons_dir
-    ])
-
-    os.unlink(tgz_path)
-
-if __name__ == '__main__':
-    sys.exit(main())

packages/flutter/lib/widgets/icon.dart

@@ -41,7 +41,7 @@ class IconTheme extends Inherited {
 AssetBundle _initIconBundle() {
   if (rootBundle != null)
     return rootBundle;
-  const String _kAssetBase = '/packages/sky/assets/material-design-icons/';
+  const String _kAssetBase = '/packages/material_design_icons/icons/';
   return new NetworkAssetBundle(Uri.base.resolve(_kAssetBase));
 }
 

packages/flutter/pubspec.yaml

@@ -5,6 +5,7 @@ description: A framework for writing Sky applications
 homepage: https://github.com/domokit/sky_engine/tree/master/sky/sdk
 dependencies:
   cassowary: ^0.1.7
+  material_design_icons: ^0.0.1
   mojo_services: ^0.0.15
   mojo: ^0.0.17
   mojom: ^0.0.17