Move sky/examples to sky/sdk/lib/example, and code changes to support that change. Fixes T277.

sky/examples/rendering/shadowed_box.dart

Index: sky/examples/rendering/shadowed_box.dart
diff --git a/sky/examples/rendering/shadowed_box.dart b/sky/examples/rendering/shadowed_box.dart
deleted file mode 100644
index 4a156fa4b920b8d18eae26aff192a877bb43cf9d..0000000000000000000000000000000000000000
--- a/sky/examples/rendering/shadowed_box.dart
+++ /dev/null
@@ -1,30 +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 'dart:sky';
-
-import 'package:sky/rendering/box.dart';
-import 'package:sky/rendering/flex.dart';
-import 'package:sky/rendering/sky_binding.dart';
-import 'package:sky/theme/colors.dart';
-import 'package:sky/theme/shadows.dart';
-
-void main() {
-  var coloredBox = new RenderDecoratedBox(
-    decoration: new BoxDecoration(
-      gradient: new RadialGradient(
-        center: Point.origin, radius: 500.0,
-        colors: [Yellow[500], Blue[500]]),
-      boxShadow: shadows[3])
-  );
-  var paddedBox = new RenderPadding(
-    padding: const EdgeDims.all(50.0),
-    child: coloredBox);
-  new SkyBinding(root: new RenderDecoratedBox(
-    decoration: const BoxDecoration(
-      backgroundColor: const Color(0xFFFFFFFF)
-    ),
-    child: paddedBox
-  ));
-}