ChromeOS: Implement minumal material design OOBE.

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

Index: chrome/browser/resources/chromeos/login/oobe_welcome.css
diff --git a/chrome/browser/resources/chromeos/login/oobe_welcome.css b/chrome/browser/resources/chromeos/login/oobe_welcome.css
new file mode 100644
index 0000000000000000000000000000000000000000..2dcf4b1dbff7cbbe0cebea35ae946f050685fbba
--- /dev/null
+++ b/chrome/browser/resources/chromeos/login/oobe_welcome.css
@@ -0,0 +1,26 @@
+/* Copyright 2016 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. */
+
+:host {
+  display: flex;
+  flex-direction: column;
+  font-size: 18px;
+  overflow: hidden;
+  position: relative;
+}
+
+#oobe-welcome-md .buttonbox {
+  font-size: 32px;
+  padding: 15px 24px 24px;
+  width: 100px;
+}
+
+#oobe-welcome-md .welcome-next {
+  padding: 15px 24px 24px;
+}
+
+#oobe-welcome-md .bottom-button {
+    --iron-icon-height: 32px;
+    --iron-icon-width: 32px;
+}