Add skeleton UI for sync page.

chrome/browser/resources/settings/sync_page/sync_page.css

Index: chrome/browser/resources/settings/sync_page/sync_page.css
diff --git a/chrome/browser/resources/settings/sync_page/sync_page.css b/chrome/browser/resources/settings/sync_page/sync_page.css
new file mode 100644
index 0000000000000000000000000000000000000000..3cf92e790e5fd5f581df168c9fa463914be0c230
--- /dev/null
+++ b/chrome/browser/resources/settings/sync_page/sync_page.css
@@ -0,0 +1,22 @@
+/* Copyright (c) 2015 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-radio-button {
+  display: block;
+}
+
+.checkbox-container {
+  display: flex;
+  flex-flow: column;
+}
+
+.checkbox-container-row {
+  display: flex;
+}
+
+.checkbox-container-row > cr-checkbox {
+  display: flex;
+  flex-basis: 0;
+  flex-grow: 1;
+}