ChromeOS: Implement minumal material design OOBE.

chrome/browser/resources/chromeos/login/oobe_button.css

Index: chrome/browser/resources/chromeos/login/oobe_button.css
diff --git a/tools/android/loading/trace_test/tests/3c.js b/chrome/browser/resources/chromeos/login/oobe_button.css
similarity index 57%
copy from tools/android/loading/trace_test/tests/3c.js
copy to chrome/browser/resources/chromeos/login/oobe_button.css
index b34da79f15c5e87fca4f4e72ae567f85c872d097..8c6167be69cecce4f503681fd4a462b20a305953 100644
--- a/tools/android/loading/trace_test/tests/3c.js
+++ b/chrome/browser/resources/chromeos/login/oobe_button.css
@@ -3,6 +3,12 @@
  * found in the LICENSE file.
  */
 
-function fn3() {
-  document.getElementById('img3').setAttribute('src', '3c.jpg');
+:host {
+  display: inline-block;
+}
+
+paper-fab {
+  background-color: var(--google-blue-500);
+  color: white;
+  font-size: 14px;
 }