Implement a basic UI flow for cryptohome encryption migration.

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

Index: chrome/browser/resources/chromeos/login/encryption_migration.css
diff --git a/chrome/browser/resources/chromeos/login/encryption_migration.css b/chrome/browser/resources/chromeos/login/encryption_migration.css
new file mode 100644
index 0000000000000000000000000000000000000000..41bd2f870f5327cb0a686318224789452c1d67b6
--- /dev/null
+++ b/chrome/browser/resources/chromeos/login/encryption_migration.css
@@ -0,0 +1,14 @@
+/* Copyright 2017 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. */
+
+paper-progress {
+  --paper-progress-active-color: var(--google-blue-500);
+  bottom: 0;
+  height: 3px;
+  width: 100%;
+}
+
+.bottom-buttons {
+  -webkit-padding-end: 16px;
+}