[MD Bookmarks] Add keyboard navigation to sidebar.

chrome/browser/resources/md_bookmarks/app.js

Index: chrome/browser/resources/md_bookmarks/app.js
diff --git a/chrome/browser/resources/md_bookmarks/app.js b/chrome/browser/resources/md_bookmarks/app.js
index a9723f10fae31797f346ba62140e921992fa2f1b..c50e6aabd1e2b58590607adee8c332cb655e9c4d 100644
--- a/chrome/browser/resources/md_bookmarks/app.js
+++ b/chrome/browser/resources/md_bookmarks/app.js
@@ -26,12 +26,19 @@ Polymer({
     sidebarWidth_: String,
   },
 
+  listeners: {
+    'folder-node-focus-changed': 'onFolderNodeFocusChanged_',
+  },
+
   /** @private{?function(!Event)} */
   boundUpdateSidebarWidth_: null,
 
   /** @private {bookmarks.DNDManager} */
   dndManager_: null,
 
+  /** @private {BookmarksFolderNode} */
+  focusedFolderNode_: null,
+
   /** @override */
   attached: function() {
     this.watch('searchTerm_', function(store) {
@@ -99,6 +106,14 @@ Polymer({
     window.addEventListener('resize', this.boundUpdateSidebarWidth_);
   },
 
+  onFolderNodeFocusChanged_: function(e) {
+    if (this.focusedFolderNode_)
+      this.focusedFolderNode_.focusable = false;
+
+    this.focusedFolderNode_ = e.detail;
+    this.focusedFolderNode_ = true;

[tsergeant, 2017/04/19 01:42:16]

What's going on here? My guess is this was supposed to be

this.focusedFolderNode_.focusable = true;

?

[calamity, 2017/04/19 04:51:02]

Done.

+  },
+
   /** @private */
   updateSidebarWidth_: function() {
     this.sidebarWidth_ =