[MD Extensions] Implement keyboard shortcuts page

chrome/test/data/webui/extensions/extension_test_util.js

Index: chrome/test/data/webui/extensions/extension_test_util.js
diff --git a/chrome/test/data/webui/extensions/extension_test_util.js b/chrome/test/data/webui/extensions/extension_test_util.js
index 84c66b89bdb0fb190aa971142b3a84df023e9de7..8fe44b708ad445f33a8c88bae9c7eb798ccf54e5 100644
--- a/chrome/test/data/webui/extensions/extension_test_util.js
+++ b/chrome/test/data/webui/extensions/extension_test_util.js
@@ -29,6 +29,55 @@ cr.define('extension_test_util', function() {
   };
 
   /**
+   * A mock to test receiving expected events and verify that they were called
+   * with the proper detail values.
+   */
+  function ListenerMock() {}
+
+  ListenerMock.prototype = {
+    /** @private {<string, {satisfied: boolean, args: !Object}} */

[michaelpg, 2016/07/01 21:39:04]

i think you mean:

/** @private {Object<{satisfied: boolean, args: !Object}>} */

lmk if it's unclear why

[Devlin, 2016/07/07 00:33:37]

Yeah, that thing. ;)  Done.

+    listeners_: {},
+
+    /**
+     * @param {string} eventName
+     * @param {Event} e
+     */
+    onEvent_: function(eventName, e) {
+      assert(this.listeners_.hasOwnProperty(eventName));
+      if (this.listeners_[eventName].satisfied) {
+        // Event was already called and checked. We could always make this
+        // more intelligent by allowing for subsequent calls, removing the
+        // listener, etc, but there's no need right now.
+        return;
+      }
+      var expected = this.listeners_[eventName].args;
+      expectDeepEquals(e.detail, expected);
+      this.listeners_[eventName].satisfied = true;
+    },
+
+    /**
+     * Adds an expected event.
+     * @param {!EventTarget} target
+     * @param {string} eventName
+     * @param {?Object} eventArgs
+     */
+    addListener: function(target, eventName, eventArgs) {
+      this.listeners_[eventName] = {args: eventArgs || {}, satisfied: false};

[michaelpg, 2016/07/01 21:39:04]

maybe assert eventName not in this.listeners_?

[Devlin, 2016/07/07 00:33:36]

Done.

+      target.addEventListener(eventName, this.onEvent_.bind(this, eventName));
+    },
+
+    /** Verifies the expectations set. */
+    verify: function() {
+      var missingEvents = [];
+      for (var key in this.listeners_) {
+        if (!this.listeners_[key].satisfied)
+          missingEvents.push(key);
+      }
+      expectEquals(0, missingEvents.length, JSON.stringify(missingEvents));
+    },
+  }
+
+  /**
    * A mock delegate for the item, capable of testing functionality.
    * @constructor
    * @extends {ClickMock}
@@ -146,6 +195,7 @@ cr.define('extension_test_util', function() {
 
   return {
     ClickMock: ClickMock,
+    ListenerMock: ListenerMock,
     MockItemDelegate: MockItemDelegate,
     isVisible: isVisible,
     testVisible: testVisible,