Refactor overall test suite, use replaceApp in HistoryListTest

chrome/browser/resources/md_history/app.js

Index: chrome/browser/resources/md_history/app.js
diff --git a/chrome/browser/resources/md_history/app.js b/chrome/browser/resources/md_history/app.js
index c0dbb18a500611cfc0f8a7e112cfe6348a483d02..774449360b619897bc8e7d218b9c3103bbe8e5a1 100644
--- a/chrome/browser/resources/md_history/app.js
+++ b/chrome/browser/resources/md_history/app.js
@@ -107,13 +107,28 @@ Polymer({
     'unselect-all': 'unselectAll',
   },
 
+  /** @private {?function(!Event)} */
+  onCanExecuteListener_: null,
+
+  /** @private {?function(!Event)} */
+  onCommandListener_: null,
+
   /** @override */
-  ready: function() {
+  attached: function() {
     this.grouped_ = loadTimeData.getBoolean('groupByDomain');
 
     cr.ui.decorate('command', cr.ui.Command);
-    document.addEventListener('canExecute', this.onCanExecute_.bind(this));
-    document.addEventListener('command', this.onCommand_.bind(this));
+    this.onCanExecuteListener_ = this.onCanExecute_.bind(this);

[Dan Beam, 2016/11/03 18:07:51]

nit: boundOnCanExecute_ seems to be the typical polymer way (except for, you
know, the _ at the end like the JS style guide likes)

[tsergeant, 2016/11/03 22:34:32]

Done.

+    this.onCommandListener_ = this.onCommand_.bind(this);
+
+    document.addEventListener('canExecute', this.onCanExecuteListener_);
+    document.addEventListener('command', this.onCommandListener_);
+  },
+
+  /** @override */
+  detached: function() {
+    document.removeEventListener('canExecute', this.onCanExecuteListener_);
+    document.removeEventListener('command', this.onCommandListener_);
   },
 
   onFirstRender: function() {