Make cr.ui.Focus* play nice with Shadow DOM and MD chrome://downloads

chrome/browser/resources/md_downloads/item.js

Index: chrome/browser/resources/md_downloads/item.js
diff --git a/chrome/browser/resources/md_downloads/item.js b/chrome/browser/resources/md_downloads/item.js
index 478667b32b052a75c27b611c0838b8dea6afae1a..8cbc084ae9cedf818f87cb0fb7c638c1719df9aa 100644
--- a/chrome/browser/resources/md_downloads/item.js
+++ b/chrome/browser/resources/md_downloads/item.js
@@ -25,6 +25,15 @@ cr.define('downloads', function() {
         value: false,
       },
 
+      readyPromise: {
+        type: Object,
+        value: function() {
+          return new Promise(function(resolve, reject) {
+            this.resolveReadyPromise_ = resolve;
+          }.bind(this));
+        },
+      },
+
       scrollbarWidth: {
         type: Number,
         value: 0,
@@ -45,6 +54,11 @@ cr.define('downloads', function() {
       isMalware_: Boolean,
     },
 
+    ready: function() {
+      this.content = this.$.content;
+      this.resolveReadyPromise_();
+    },
+
     /** @param {!downloads.Data} data */
     update: function(data) {
       assert(!this.id_ || data.id == this.id_);
@@ -130,7 +144,6 @@ cr.define('downloads', function() {
         if (controlledByExtension) {
           var link = this.$['controlled-by'].querySelector('a');
           link.href = 'chrome://extensions#' + data.by_ext_id;
-          link.setAttribute('focus-type', 'controlled-by');
           link.textContent = data.by_ext_name;
         }