Add Throbber control for DOMUI. Use it everywhere in options and in Sync setup UI.

chrome/browser/resources/shared/css/throbber.css

Index: chrome/browser/resources/shared/css/throbber.css
diff --git a/chrome/browser/resources/shared/css/throbber.css b/chrome/browser/resources/shared/css/throbber.css
new file mode 100644
index 0000000000000000000000000000000000000000..5c84e774533541d7c3fc3a5447f78c012289a3d6
--- /dev/null
+++ b/chrome/browser/resources/shared/css/throbber.css
@@ -0,0 +1,17 @@
+.throbber {
+  -webkit-animation: throbber-animation 1s steps(36, end) 0 infinite;
+  background-image: url("../../../../../app/resources/throbber.png");
+  background-position: 0;
+  display: inline-block;
+  height: 16px;
+  width: 16px;
+}
+
+@-webkit-keyframes throbber-animation {
+  from {
+    background-position-x: 0;
+  }
+  to {
+    background-position-x: -576px;
+  }
+}