Inject automatically on install etc., add mime types, and fix nits.

go-back-with-backspace/pages/installed.js

Index: go-back-with-backspace/pages/installed.js
diff --git a/go-back-with-backspace/pages/installed.js b/go-back-with-backspace/pages/installed.js
deleted file mode 100644
index b06905063ee4b410218bcff779631f8e9ca12adb..0000000000000000000000000000000000000000
--- a/go-back-with-backspace/pages/installed.js
+++ /dev/null
@@ -1,19 +0,0 @@
-// 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.
-
-// Initialize the page.
-function init() {
-  LoadInternationalizedStrings();
-
-  document.getElementById('report_page').onclick = function() {
-    reportPage();
-  };
-
-  document.getElementById('open_options').onclick = function() {
-    chrome.runtime.openOptionsPage();
-  };
-
-}
-
-window.addEventListener('load', init, false);