Add a basic Dialog

sky/tests/widgets/dialog-expected.txt

Index: sky/tests/widgets/dialog-expected.txt
diff --git a/sky/tests/widgets/dialog-expected.txt b/sky/tests/widgets/dialog-expected.txt
new file mode 100644
index 0000000000000000000000000000000000000000..0c76eb7d078abc1b03524fc5ad16e0bd8e83b6d7
--- /dev/null
+++ b/sky/tests/widgets/dialog-expected.txt
@@ -0,0 +1,24 @@
+CONSOLE: TestRenderView enabled
+CONSOLE: 
+PAINT FOR FRAME #1 ----------------------------------------------
+1 | TestDisplayList() constructor: 800.0 x 600.0
+------------------------------------------------------------------------
+CONSOLE: 
+PAINT FOR FRAME #2 ----------------------------------------------
+2 | TestDisplayList() constructor: 800.0 x 600.0
+2 | paintChild RenderStack at Point(0.0, 0.0)
+2 |  | TestDisplayList() constructor: 800.0 x 600.0
+2 |  | paintChild RenderDecoratedBox at Point(0.0, 0.0)
+2 |  |  | TestDisplayList() constructor: 800.0 x 600.0
+2 |  |  | drawRect(Rect.fromLTRB(0.0, 0.0, 800.0, 600.0), Paint(Color(0x7f000000)))
+2 |  | paintChild RenderPositionedBox at Point(0.0, 0.0)
+2 |  |  | TestDisplayList() constructor: 800.0 x 600.0
+2 |  |  | paintChild RenderConstrainedBox at Point(260.0, 284.0)
+2 |  |  |  | TestDisplayList() constructor: 800.0 x 600.0
+2 |  |  |  | drawRRect(Instance of 'RRect', Paint(Color(0xfffafafa)))
+2 |  |  |  | paintChild RenderParagraph at Point(0.0, 0.0)
+2 |  |  |  |  | TestDisplayList() constructor: 800.0 x 600.0
+2 |  |  |  | paintChild RenderParagraph at Point(0.0, 16.0)
+2 |  |  |  |  | TestDisplayList() constructor: 800.0 x 600.0
+------------------------------------------------------------------------
+PAINTED 2 FRAMES