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

sky/examples/lib/solid_color_box.dart

-// 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' as sky;
-import 'package:sky/rendering/object.dart';
-import 'package:sky/rendering/box.dart';
-
-class RenderSolidColorBox extends RenderDecoratedBox {
-  final Size desiredSize;
-  final Color backgroundColor;
-
-  RenderSolidColorBox(Color backgroundColor, { this.desiredSize: Size.infinite })
-      : backgroundColor = backgroundColor,
-        super(decoration: new BoxDecoration(backgroundColor: backgroundColor));
-
-  double getMinIntrinsicWidth(BoxConstraints constraints) {
-    return constraints.constrainHeight(
-      this.desiredSize == Size.infinite ? 0.0 : desiredSize.width
-    );
-  }
-
-  double getMaxIntrinsicWidth(BoxConstraints constraints) {
-    return constraints.constrainWidth(
-      this.desiredSize == Size.infinite ? 0.0 : desiredSize.width
-    );
-  }
-
-  double getMinIntrinsicHeight(BoxConstraints constraints) {
-    return constraints.constrainHeight(
-      this.desiredSize == Size.infinite ? 0.0 : desiredSize.height
-    );
-  }
-
-  double getMaxIntrinsicHeight(BoxConstraints constraints) {
-    return constraints.constrainHeight(
-      this.desiredSize == Size.infinite ? 0.0 : desiredSize.height
-    );
-  }
-
-  void performLayout() {
-    size = constraints.constrain(desiredSize);
-  }
-
-  void handleEvent(sky.Event event, BoxHitTestEntry entry) {
-    if (event.type == 'pointerdown')
-      decoration = new BoxDecoration(backgroundColor: const Color(0xFFFF0000));
-    else if (event.type == 'pointerup')
-      decoration = new BoxDecoration(backgroundColor: backgroundColor);
-  }
-}