Revert of [Contextual Search] Remove opt-in code.

chrome/browser/resources/contextual_search/promo.js

+/* Copyright 2014 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.
+*/
+
+<include src="../../../../ui/webui/resources/js/util.js">
+<include src="../../../../ui/webui/resources/js/load_time_data.js">
+
+/**
+ * The amount of delay to use in the opt-in action in order to give time for
+ * the fade-out animation to execute, before navigating to the opt-in URL,
+ * in milliseconds.
+ * @const
+ */
+var OPT_IN_DELAY_MS = 65;
+
+/**
+ * Once the DOM is loaded, determine if the header image is to be kept and
+ * register a handler to add the 'hide' class to the container element in order
+ * to hide it.
+ */
+document.addEventListener('DOMContentLoaded', function(event) {
+  if (config['hideHeader']) {
+    removeHeaderImages();
+  }
+  $('optin-button').addEventListener('click', function() {
+    $('container').classList.add('hide');
+    setTimeout(function() {
+      location.hash = 'optin';
+    }, OPT_IN_DELAY_MS);
+  });
+  $('optout-button').addEventListener('click', function() {
+    location.hash = 'optout';
+  });
+});
+
+/**
+ * Returns the height of the content. Method called from Chrome to properly size
+ * the view embedding it.
+ * @return {number} The height of the content, in pixels.
+ */
+function getContentHeight() {
+  return $('container').clientHeight;
+}
+
+/**
+ * Removes all header images from the promo.
+ */
+function removeHeaderImages() {
+  var images = document.querySelectorAll('.header-image');
+  for (var i = 0, length = images.length; i < length; i++) {
+    var image = images[i];
+    var parent = image.parentElement;
+    if (parent) {
+      parent.removeChild(image);
+    }
+  }
+}