adding game_of_life sample

dart/samples/webcomponents/game_of_life/styles.css

Index: dart/samples/webcomponents/game_of_life/styles.css
diff --git a/dart/samples/webcomponents/game_of_life/styles.css b/dart/samples/webcomponents/game_of_life/styles.css
new file mode 100644
index 0000000000000000000000000000000000000000..48f0f34d2a39dd5d9b1d6bf1dac54caf8092b47c
--- /dev/null
+++ b/dart/samples/webcomponents/game_of_life/styles.css
@@ -0,0 +1,18 @@
+/* Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file */
+/* for details. All rights reserved. Use of this source code is governed by a */
+/* BSD-style license that can be found in the LICENSE file. */
+
+.cell {
+  position: absolute;
+  width: 20px;
+  height: 20px;
+  border: 1px solid gray;
+}
+
+.alive {
+  background-color: black;
+}
+
+#panel {
+  position: absolute;
+}