Add chrome://site-engagement WebUI.

chrome/browser/resources/engagement/site_engagement.css

Index: chrome/browser/resources/engagement/site_engagement.css
diff --git a/chrome/browser/resources/engagement/site_engagement.css b/chrome/browser/resources/engagement/site_engagement.css
new file mode 100644
index 0000000000000000000000000000000000000000..cf6e4db189a0f97823c888c3874c2c4f67e868f0
--- /dev/null
+++ b/chrome/browser/resources/engagement/site_engagement.css
@@ -0,0 +1,20 @@
+/* Copyright 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. */
+
+table,
+table td,
+table th {
+border: 1px solid #777;
+border-collapse: collapse;
+padding-left: 4px;
+padding-right: 4px;
+}
+
+table th {
+background: rgb(224,236,255);
+}
+
+.origin-cell {
+min-width: 500px;
+}