[Icons NTP] Make Fast Local NTP render largeIconUrl instead of thumbnail, if available.

This is the fast local NTP counterpart to https://crrev.com/1013173003.

BUG=467712

Review URL: https://codereview.chromium.org/1029583003

Cr-Commit-Position: refs/heads/master@{#321861}

chrome/browser/resources/local_ntp/most_visited_single.css

@@ -151,13 +151,24 @@ html[dir=rtl] .mv-title[style*='direction: rtl'] {
   width: 148px;
 }
 
-.mv-thumb img {
+.mv-thumb img.thumbnail {
   height: auto;
   min-height: 100%;
   width: 100%;
 }
 
-.mv-thumb.failed-img {
+.mv-thumb img.large-icon {
+  height: 48px;
+  left: 50%;
+  margin-left: -24px;
+  margin-top: -24px;
+  position: absolute;
+  top: 50%;
+  width: 48px;
+}
+
+.mv-thumb.failed-img,
+.mv-thumb.large-icon-outer {
   background-color: #fff;
   height: 94px;
   width: 148px;

chrome/browser/resources/local_ntp/most_visited_single.js

@@ -279,12 +279,23 @@ var renderTile = function(data) {
   title.style.direction = data.direction || 'ltr';
 
   var thumb = tile.querySelector('.mv-thumb');
-  if (data.thumbnailUrl) {
+  if (data.largeIconUrl || data.thumbnailUrl) {
     var img = document.createElement('img');
     img.title = data.title;
-    img.src = data.thumbnailUrl;
+    if (data.largeIconUrl) {
+      img.src = data.largeIconUrl;
+      img.classList.add('large-icon');
+    } else {
+      img.src = data.thumbnailUrl;
+      img.classList.add('thumbnail');
+    }
     loadedCounter += 1;
     img.addEventListener('load', countLoad);
+    if (data.largeIconUrl) {
+      img.addEventListener('load', function(ev) {
+        thumb.classList.add('large-icon-outer');
+      });
+    }
     img.addEventListener('error', countLoad);
     img.addEventListener('error', function(ev) {
       thumb.classList.add('failed-img');

chrome/browser/resources/local_ntp/most_visited_thumbnail.css

@@ -46,9 +46,7 @@ img.large-icon {
   left: 50%;
   margin-left: -24px;
   margin-top: -24px;
-  min-height: initial;
   position: absolute;
   top: 50%;
-  vertical-align: middle;
   width: 48px;
 }