[MD History] Make sidebar menu respond to spacebar.

chrome/browser/resources/md_history/app.crisper.js

Index: chrome/browser/resources/md_history/app.crisper.js
diff --git a/chrome/browser/resources/md_history/app.crisper.js b/chrome/browser/resources/md_history/app.crisper.js
index b8422e555254173f9ef6d916297f45c6bd7ad7ab..e76cd7a5c654f9688ef4d99cde69d6b2d47e3362 100644
--- a/chrome/browser/resources/md_history/app.crisper.js
+++ b/chrome/browser/resources/md_history/app.crisper.js
@@ -8542,6 +8542,7 @@ Polymer({
 // found in the LICENSE file.
 Polymer({
   is: 'history-side-bar',
+  behaviors: [ Polymer.IronA11yKeysBehavior ],
   properties: {
     selectedPage: {
       type: String,
@@ -8554,6 +8555,12 @@ Polymer({
       reflectToAttribute: true
     }
   },
+  keyBindings: {
+    'space:keydown': 'onSpacePressed_'
+  },
+  onSpacePressed_: function(e) {
+    e.detail.keyboardEvent.path[0].click();
+  },
   onSelectorActivate_: function() {
     this.fire('history-close-drawer');
   },