Rationalize Dart mojo and sky package structure

sky/framework/elements/sky-icon.sky

Index: sky/framework/elements/sky-icon.sky
diff --git a/sky/framework/elements/sky-icon.sky b/sky/framework/elements/sky-icon.sky
deleted file mode 100644
index dd2a10f7f656e64ea1ef3dc92ee892250c3662ad..0000000000000000000000000000000000000000
--- a/sky/framework/elements/sky-icon.sky
+++ /dev/null
@@ -1,57 +0,0 @@
-<!--
-// 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 src="sky-element.sky" />
-
-<sky-element attributes="type:string, size:number">
-<template>
-  <img />
-</template>
-<script>
-import "dart:sky";
-
-const String kAssetBase = '/sky/assets/material-design-icons';
-
-@Tagname('sky-icon')
-class SkyIcon extends SkyElement {
-  Element _img;
-
-  void _setSize(int size) {
-    _img.style['height'] = '${size}px';
-    _img.style['width'] = '${size}px';
-  }
-
-  void _setSrc(String type, int size) {
-    List<String> parts = type.split('/');
-    if (parts.length < 2)
-      return;
-    String category = parts[0];
-    String subtype = parts[1];
-    _img.src = '${kAssetBase}/${category}/2x_web/ic_${subtype}_${size}dp.png';
-  }
-
-  void shadowRootReady() {
-    _img = shadowRoot.firstElementChild;
-    int size = this.size.floor();
-    _setSize(size);
-    _setSrc(type, size);
-  }
-
-  void typeChanged(String oldValue, String newValue) {
-    if (_img != null)
-      _setSrc(newValue, size.floor());
-  }
-
-  void sizeChanged(double oldValue, double newValue) {
-    if (_img != null) {
-      _setSize(newValue.floor());
-      _setSrc(type, newValue.floor());
-    }
-  }
-}
-
-_init(script) => register(script, SkyIcon);
-</script>
-</sky-element>