Add finch flag for rendering a recently closed link on the local ntp.

chrome/browser/resources/local_ntp/local_ntp.js

Index: chrome/browser/resources/local_ntp/local_ntp.js
diff --git a/chrome/browser/resources/local_ntp/local_ntp.js b/chrome/browser/resources/local_ntp/local_ntp.js
index e6747c55eaae760d3be58060a5e23313468d5091..717be1783d4d39d8addc6a0d6a3f1ddac340a722 100644
--- a/chrome/browser/resources/local_ntp/local_ntp.js
+++ b/chrome/browser/resources/local_ntp/local_ntp.js
@@ -30,6 +30,7 @@ var CLASSES = {
   FAKEBOX_DISABLE: 'fakebox-disable', // Makes fakebox non-interactive
   FAKEBOX_FOCUS: 'fakebox-focused', // Applies focus styles to the fakebox
   FAVICON: 'mv-favicon',
+  HIDE_ATTRIBUTION: 'attribution-hide',
   HIDE_BLACKLIST_BUTTON: 'mv-x-hide', // hides blacklist button during animation
   HIDE_FAKEBOX_AND_LOGO: 'hide-fakebox-logo',
   HIDE_NOTIFICATION: 'mv-notice-hide',
@@ -53,12 +54,15 @@ var CLASSES = {
  */
 var IDS = {
   ATTRIBUTION: 'attribution',
+  ATTRIBUTION_TEXT: 'attribution-text',
   FAKEBOX: 'fakebox',
+  FOOTER: 'footer',
   LOGO: 'logo',
   NOTIFICATION: 'mv-notice',
   NOTIFICATION_CLOSE_BUTTON: 'mv-notice-x',
   NOTIFICATION_MESSAGE: 'mv-msg',
   NTP_CONTENTS: 'ntp-contents',
+  RECENT_TABS: 'recent-tabs',
   RESTORE_ALL_LINK: 'mv-restore',
   TILES: 'mv-tiles',
   UNDO_LINK: 'mv-undo'
@@ -89,6 +93,24 @@ var NTP_DISPOSE_STATE = {
 
 
 /**
+ * The JavaScript button event value for a middle click.
+ * @type {number}
+ * @const
+ */
+var MIDDLE_MOUSE_BUTTON = 1;
+
+
+/**
+ * Possible behaviors for navigateContentWindow.
+ * @enum {number}
+ */
+var WindowOpenDisposition = {
+  CURRENT_TAB: 1,
+  NEW_BACKGROUND_TAB: 2
+};
+
+
+/**
  * The container for the tile elements.
  * @type {Element}
  */
@@ -343,7 +365,7 @@ function onThemeChange() {
  */
 function updateAttribution(url) {
   if (!url) {
-    attribution.hidden = true;
+    attribution.classList.add(CLASSES.HIDE_ATTRIBUTION);

[Jered, 2013/06/24 17:42:26]

nit: This change seems unnecessary in the context of this CL.

[jeremycho, 2013/06/24 20:12:09]

This is for setting display:none when no attribution is present.  With hidden,
it was still taking up space.

     return;
   }
   var attributionImage = new Image();
@@ -352,10 +374,10 @@ function updateAttribution(url) {
     if (oldAttributionImage)
       removeNode(oldAttributionImage);
     attribution.appendChild(attributionImage);
-    attribution.hidden = false;
+    attribution.classList.remove(CLASSES.HIDE_ATTRIBUTION);
   };
   attributionImage.onerror = function() {
-    attribution.hidden = true;
+    attribution.classList.add(CLASSES.HIDE_ATTRIBUTION);
   };
   attributionImage.src = url;
 }
@@ -863,6 +885,19 @@ function isGooglePage() {
 
 
 /**
+ * Extract the desired navigation behavior from a click button.
+ * @param {number} button The Event#button property of a click event.
+ * @return {WindowOpenDisposition} The desired behavior for
+ *     navigateContentWindow.
+ */
+function getDispositionFromClickButton(button) {
+  if (button == MIDDLE_MOUSE_BUTTON)
+    return WindowOpenDisposition.NEW_BACKGROUND_TAB;
+  return WindowOpenDisposition.CURRENT_TAB;
+}
+
+
+/**
  * Prepares the New Tab Page by adding listeners, rendering the current
  * theme, the most visited pages section, and Google-specific elements for a
  * Google-provided page.
@@ -895,6 +930,18 @@ function init() {
     document.body.classList.add(CLASSES.NON_GOOGLE_PAGE);
   }
 
+  var recentTabsText = templateData.recentTabs;
+  if (recentTabsText) {
+    var recentTabsLink = document.createElement('span');
+    recentTabsLink.id = IDS.RECENT_TABS;
+    recentTabsLink.addEventListener('click', function(event) {
+      ntpApiHandle.navigateContentWindow(
+          'chrome://history', getDispositionFromClickButton(event.button));
+    });
+    recentTabsLink.textContent = recentTabsText;
+    var footer = $(IDS.FOOTER);
+    footer.insertBefore(recentTabsLink, footer.firstChild);
+  }
 
   var notificationMessage = $(IDS.NOTIFICATION_MESSAGE);
   notificationMessage.textContent = templateData.thumbnailRemovedNotification;
@@ -906,7 +953,7 @@ function init() {
   restoreAllLink.addEventListener('click', onRestoreAll);
   registerKeyHandler(restoreAllLink, KEYCODE.ENTER, onUndo);
   restoreAllLink.textContent = templateData.restoreThumbnailsShort;
-  attribution.textContent = templateData.attributionIntro;
+  $(IDS.ATTRIBUTION_TEXT).textContent = templateData.attributionIntro;
 
   var notificationCloseButton = $(IDS.NOTIFICATION_CLOSE_BUTTON);
   notificationCloseButton.addEventListener('click', hideNotification);