Add options and a browser-action popup.

go-back-with-backspace/pages/options.css

Index: go-back-with-backspace/pages/options.css
diff --git a/go-back-with-backspace/pages/options.css b/go-back-with-backspace/pages/options.css
new file mode 100644
index 0000000000000000000000000000000000000000..936a4613792c9834d1b9f4af67d80e84bc15b6cd
--- /dev/null
+++ b/go-back-with-backspace/pages/options.css
@@ -0,0 +1,41 @@
+/**
+ * Copyright 2016 Google Inc. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+body {
+  padding: 10px;
+  direction: __MSG_@@bidi_dir__;
+}
+
+textarea {
+  width: 100%;
+  margin: 0;
+  padding: 0;
+}
+
+.applets {
+  padding-top: 20px;
+}
+
+.whitelist {
+  padding-top: 10px;
+  padding-__MSG_@@bidi_start_edge__: 40px;
+}
+
+.buttons {
+  padding-top: 2px;
+  padding-bottom: 1px;
+  padding-__MSG_@@bidi_start_edge__: 20px;
+  padding-__MSG_@@bidi_end_edge__: 0px;
+  text-align: __MSG_@@bidi_end_edge__;
+}
+
+#error {
+  color: red;
+}
+
+#report_page {
+  float: __MSG_@@bidi_start_edge__;
+}