Promote Apps Developer Tools in the chrome:extensions page

chrome/browser/resources/extensions/extensions.js

Index: chrome/browser/resources/extensions/extensions.js
diff --git a/chrome/browser/resources/extensions/extensions.js b/chrome/browser/resources/extensions/extensions.js
index 97bb296b225a3663fd703fa628829ed463b771ca..59a14daa8833796047093dd128dc18b4dea3a510 100644
--- a/chrome/browser/resources/extensions/extensions.js
+++ b/chrome/browser/resources/extensions/extensions.js
@@ -86,6 +86,13 @@ cr.define('extensions', function() {
     __proto__: HTMLDivElement.prototype,
 
     /**
+     * Whether the App Developer Tools promo has been dismissed on this page.
+     * @type {boolean}
+     * @private
+     */
+    promoDismissed_: false,
+
+    /**
      * Perform initial setup.
      */
     initialize: function() {
@@ -114,6 +121,13 @@ cr.define('extensions', function() {
       $('update-extensions-now').addEventListener('click',
           this.handleUpdateExtensionNow_.bind(this));
 
+      // Set up the close dialog for the apps developer tools promo.
+      $('apps-developer-tools-promo').querySelector('.close-button').
+          addEventListener('click', function(e) {
+        this.promoDismissed_ = true;
+        $('extension-settings').classList.remove('adt-promo');
+      }.bind(this));
+
       if (!loadTimeData.getBoolean('offStoreInstallEnabled')) {
         this.dragWrapper_ = new cr.ui.DragWrapper(document.documentElement,
                                                   dragWrapperHandler);
@@ -297,6 +311,9 @@ cr.define('extensions', function() {
       $('toggle-dev-on').checked = false;
     }
 
+    var showPromo = extensionsData.promoteAppsDevTools && !this.promoDismissed_;
+    pageDiv.classList.toggle('adt-promo', showPromo);
+
     $('load-unpacked').disabled = extensionsData.loadUnpackedDisabled;
 
     ExtensionsList.prototype.data_ = extensionsData;