diff --git a/accessible/tests/mochitest/Makefile.in b/accessible/tests/mochitest/Makefile.in
index b170f7cd39e5..c60e57f48cf6 100644
--- a/accessible/tests/mochitest/Makefile.in
+++ b/accessible/tests/mochitest/Makefile.in
@@ -96,6 +96,7 @@ _TEST_FILES =\
 		test_events_doc.html \
 		test_events_draganddrop.html \
 		test_events_flush.html \
+		test_events_focus.html \
 		test_events_focus.xul \
 		test_events_mutation.html \
 		test_events_tree.xul \
diff --git a/accessible/tests/mochitest/events.js b/accessible/tests/mochitest/events.js
index 843186aa3a6b..e9ef4c55dd32 100644
--- a/accessible/tests/mochitest/events.js
+++ b/accessible/tests/mochitest/events.js
@@ -91,6 +91,7 @@ function unregisterA11yEventListener(aEventType, aEventHandler)
   listenA11yEvents(false);
 }
 
+
 ////////////////////////////////////////////////////////////////////////////////
 // Event queue
 
@@ -106,15 +107,6 @@ const INVOKER_ACTION_FAILED = 1;
  */
 const DO_NOT_FINISH_TEST = 1;
 
-/**
- * Common invoker checker (see eventSeq of eventQueue).
- */
-function invokerChecker(aEventType, aTarget)
-{
-  this.type = aEventType;
-  this.target = aTarget;
-}
-
 /**
  * Creates event queue for the given event type. The queue consists of invoker
  * objects, each of them generates the event of the event type. When queue is
@@ -539,6 +531,9 @@ function eventQueue(aEventType)
 }
 
 
+////////////////////////////////////////////////////////////////////////////////
+// Action sequence
+
 /**
  * Deal with action sequence. Used when you need to execute couple of actions
  * each after other one.
@@ -586,6 +581,168 @@ function sequence()
 }
 
 
+////////////////////////////////////////////////////////////////////////////////
+// Event queue invokers
+
+/**
+ * Invokers defined below take a checker object implementing 'check' method
+ * which will be called when proper event is handled. Invokers listen default
+ * event type registered in event queue object.
+ *
+ * Note, you don't need to initialize 'target' and 'type' members of checker
+ * object. The 'target' member will be initialized by invoker object and you are
+ * free to use it in 'check' method.
+ */
+
+/**
+ * Click invoker.
+ */
+function synthClick(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthAction(aNodeOrID, aChecker);
+
+  this.invoke = function synthClick_invoke()
+  {
+    // Scroll the node into view, otherwise synth click may fail.
+    this.DOMNode.scrollIntoView(true);
+
+    synthesizeMouse(this.DOMNode, 1, 1, {});
+  }
+
+  this.getID = function synthFocus_getID()
+  {
+    return prettyName(aNodeOrID) + " click"; 
+  }
+}
+
+/**
+ * General key press invoker.
+ */
+function synthKey(aNodeOrID, aKey, aArgs, aChecker)
+{
+  this.__proto__ = new synthAction(aNodeOrID, aChecker);
+
+  this.invoke = function synthKey_invoke()
+  {
+    synthesizeKey(this.mKey, this.mArgs);
+  }
+
+  this.getID = function synthFocus_getID()
+  {
+    return prettyName(aNodeOrID) + " '" + this.mKey + "' key"; 
+  }
+
+  this.mKey = aKey;
+  this.mArgs = aArgs ? aArgs : {};
+}
+
+/**
+ * Tab key invoker.
+ */
+function synthTab(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthKey(aNodeOrID, "VK_TAB", { shiftKey: false },
+                                aChecker);
+
+  this.getID = function synthTabTest_getID() 
+  { 
+    return prettyName(aNodeOrID) + " tab";
+  }
+}
+
+/**
+ * Shift tab key invoker.
+ */
+function synthShiftTab(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthKey(aNodeOrID, "VK_TAB", { shiftKey: true },
+                                aChecker);
+
+  this.getID = function synthTabTest_getID() 
+  { 
+    return prettyName(aNodeOrID) + " shift tab";
+  }
+}
+
+/**
+ * Down arrow key invoker.
+ */
+function synthDownKey(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthKey(aNodeOrID, "VK_DOWN", null, aChecker);
+
+  this.getID = function synthDownKey_getID()
+  {
+    return prettyName(aNodeOrID) + " key down";
+  }
+}
+
+/**
+ * Right arrow key invoker.
+ */
+function synthRightKey(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthKey(aNodeOrID, "VK_RIGHT", null, aChecker);
+
+  this.getID = function synthRightKey_getID()
+  {
+    return prettyName(aNodeOrID) + " key right";
+  }
+}
+
+/**
+ * Focus invoker.
+ */
+function synthFocus(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthAction(aNodeOrID, aChecker);
+
+  this.invoke = function synthFocus_invoke()
+  {
+    this.DOMNode.focus();
+  }
+
+  this.getID = function synthFocus_getID() 
+  { 
+    return prettyName(aNodeOrID) + " focus";
+  }
+}
+
+/**
+ * Select all invoker.
+ */
+function synthSelectAll(aNodeOrID, aChecker)
+{
+  this.__proto__ = new synthAction(aNodeOrID, aChecker);
+
+  this.invoke = function synthSelectAll_invoke()
+  {
+    if (this.DOMNode instanceof Components.interfaces.nsIDOMHTMLInputElement)
+      this.DOMNode.select();
+    else
+      window.getSelection().selectAllChildren(this.DOMNode);
+  }
+
+  this.getID = function synthSelectAll_getID()
+  {
+    return aNodeOrID + " selectall";
+  }
+}
+
+
+////////////////////////////////////////////////////////////////////////////////
+// Event queue checkers
+
+/**
+ * Common invoker checker (see eventSeq of eventQueue).
+ */
+function invokerChecker(aEventType, aTarget)
+{
+  this.type = aEventType;
+  this.target = aTarget;
+}
+
+
 ////////////////////////////////////////////////////////////////////////////////
 // Private implementation details.
 ////////////////////////////////////////////////////////////////////////////////
@@ -741,3 +898,22 @@ function sequenceItem(aProcessor, aEventType, aTarget, aItemID)
   
   this.queue.push(invoker);
 }
+
+////////////////////////////////////////////////////////////////////////////////
+// Event queue invokers
+
+/**
+ * Invoker base class for prepare an action.
+ */
+function synthAction(aNodeOrID, aChecker)
+{
+  this.DOMNode = getNode(aNodeOrID);
+  aChecker.target = this.DOMNode;
+
+  this.check = function synthAction_check(aEvent)
+  {
+    aChecker.check(aEvent);
+  }
+
+  this.getID = function synthAction_getID() { return aNodeOrID + " action"; }
+}
diff --git a/accessible/tests/mochitest/test_events_caretmove.html b/accessible/tests/mochitest/test_events_caretmove.html
index 1cd068823686..f25606426471 100644
--- a/accessible/tests/mochitest/test_events_caretmove.html
+++ b/accessible/tests/mochitest/test_events_caretmove.html
@@ -20,135 +20,37 @@
 
   <script type="application/javascript">
     /**
-     * Invoker base class.
+     * Generic checker.
      */
-    function synthAction(aNodeOrID, aCaretOffset)
+    function checker(aCaretOffset)
     {
-      this.DOMNode = getNode(aNodeOrID);
-
-      this.check = function synthAction_check(aEvent)
+      this.check = function checker_check(aEvent)
       {
         is(aEvent.QueryInterface(nsIAccessibleCaretMoveEvent).caretOffset,
-           this.caretOffset,
-           "Wrong caret offset for " + aNodeOrID);
+           aCaretOffset,
+           "Wrong caret offset for " + prettyName(aEvent.target));
       }
-
-      this.getID = function synthAction_getID() { return aNodeOrID + " action"; }
-
-      this.caretOffset = aCaretOffset;
     }
 
     /**
-     * Click invoker.
+     * Click checker.
      */
-    function synthClick(aNodeOrID, aCaretOffset,
-                        aExtraNodeOrID, aExtraCaretOffset)
+    function clickChecker(aCaretOffset, aExtraNodeOrID, aExtraCaretOffset)
     {
-      this.__proto__ = new synthAction(aNodeOrID, aCaretOffset);
+      this.__proto__ = new checker(aCaretOffset);
 
       this.extraNode = getNode(aExtraNodeOrID);
-      this.extraCaretOffset = aExtraCaretOffset;
 
-      this.invoke = function synthClick_invoke()
-      {
-        // Scroll the node into view, otherwise synth click may fail.
-        this.DOMNode.scrollIntoView(true);
-
-        synthesizeMouse(this.DOMNode, 1, 1, {});
-      }
-
-      this.check = function synthFocus_check(aEvent)
+      this.check = function clickChecker_check(aEvent)
       {
         this.__proto__.check(aEvent);
 
         if (this.extraNode) {
           var acc = getAccessible(this.extraNode, [nsIAccessibleText]);
-          is(acc.caretOffset, this.extraCaretOffset,
+          is(acc.caretOffset, aExtraCaretOffset,
              "Wrong caret offset for " + aExtraNodeOrID);
         }
       }
-
-      this.getID = function synthFocus_getID() { return aNodeOrID + " click"; }
-    }
-
-    /**
-     * Key press invokers.
-     */
-    function synthKey(aNodeOrID, aCaretOffset, aKey, aArgs)
-    {
-      this.__proto__ = new synthAction(aNodeOrID, aCaretOffset);
-  
-      this.invoke = function synthKey_invoke()
-      {
-        synthesizeKey(this.mKey, this.mArgs);
-      }
-
-      this.mKey = aKey;
-      this.mArgs = aArgs ? aArgs : {};
-    }
-
-    function synthTabTest(aNodeOrID, aCaretOffset, aBackTab)
-    {
-      this.__proto__ = new synthKey(aNodeOrID, aCaretOffset,
-                                    "VK_TAB", {shiftKey: aBackTab});
-
-      this.getID = function synthTabTest_getID() { return aNodeOrID + " tab"; }
-    }
-
-    function synthDownKey(aNodeOrID, aCaretOffset)
-    {
-      this.__proto__ = new synthKey(aNodeOrID, aCaretOffset, "VK_DOWN");
-
-      this.getID = function synthDownKey_getID()
-      {
-        return aNodeOrID + " key down";
-      }
-    }
-
-    function synthRightKey(aNodeOrID, aCaretOffset)
-    {
-      this.__proto__ = new synthKey(aNodeOrID, aCaretOffset, "VK_RIGHT");
-
-      this.getID = function synthRightKey_getID()
-      {
-        return aNodeOrID + " key right";
-      }
-    }
-
-    /**
-     * Focus invoker.
-     */
-    function synthFocus(aNodeOrID, aCaretOffset)
-    {
-      this.__proto__ = new synthAction(aNodeOrID, aCaretOffset);
-
-      this.invoke = function synthFocus_invoke()
-      {
-        this.DOMNode.focus();
-      }
-
-      this.getID = function synthFocus_getID() { return aNodeOrID + " focus"; }
-    }
-
-    /**
-     * Select all invoker.
-     */
-    function synthSelectAll(aNodeOrID, aCaretOffset)
-    {
-      this.__proto__ = new synthAction(aNodeOrID, aCaretOffset);
-
-      this.invoke = function synthSelectAll_invoke()
-      {
-        if (this.DOMNode instanceof Components.interfaces.nsIDOMHTMLInputElement)
-          this.DOMNode.select();
-        else
-          window.getSelection().selectAllChildren(this.DOMNode);
-      }
-
-      this.getID = function synthSelectAll_getID()
-      {
-        return aNodeOrID + " selectall";
-      }
     }
 
     /**
@@ -177,26 +79,27 @@
       gQueue = new eventQueue(nsIAccessibleEvent.EVENT_TEXT_CARET_MOVED);
 
       var id = "textbox";
-      gQueue.push(new synthFocus(id, 5));
-      gQueue.push(new synthSelectAll(id, 5));
-      gQueue.push(new synthClick(id, 0));
-      gQueue.push(new synthRightKey(id, 1));
+      gQueue.push(new synthFocus(id, new checker(5)));
+      gQueue.push(new synthSelectAll(id, new checker(5)));
+      gQueue.push(new synthClick(id, new checker(0)));
+      gQueue.push(new synthRightKey(id, new checker(1)));
 
       id = "textarea";
-      gQueue.push(new synthClick(id, 0));
-      gQueue.push(new synthRightKey(id, 1));
-      gQueue.push(new synthDownKey(id, 12));
+      gQueue.push(new synthClick(id, new checker(0)));
+      gQueue.push(new synthRightKey(id, new checker(1)));
+      gQueue.push(new synthDownKey(id, new checker(12)));
 
       id = "p";
-      gQueue.push(new synthClick(id, 0));
-      gQueue.push(new synthRightKey(id, 1));
-      gQueue.push(new synthDownKey(id, 6));
+      gQueue.push(new synthClick(id, new checker(0)));
+      gQueue.push(new synthRightKey(id, new checker(1)));
+      gQueue.push(new synthDownKey(id, new checker(6)));
 
-      gQueue.push(new synthClick("p1_in_div", 0, "p2_in_div", -1));
+      gQueue.push(new synthClick("p1_in_div",
+                                 new clickChecker(0, "p2_in_div", -1)));
 
-      gQueue.push(new synthTabTest("p", 0, true));
-      gQueue.push(new synthTabTest("textarea", 12, true));
-      gQueue.push(new synthTabTest("p", 0, false));
+      gQueue.push(new synthShiftTab("p", new checker(0)));
+      gQueue.push(new synthShiftTab("textarea", new checker(12)));
+      gQueue.push(new synthTab("p", new checker(0)));
 
       gQueue.invoke(); // Will call SimpleTest.finish();
     }
diff --git a/accessible/tests/mochitest/test_events_focus.html b/accessible/tests/mochitest/test_events_focus.html
new file mode 100644
index 000000000000..3acc338a9a3f
--- /dev/null
+++ b/accessible/tests/mochitest/test_events_focus.html
@@ -0,0 +1,121 @@
+<html>
+
+<head>
+  <title>Accessible focus testing</title>
+
+  <link rel="stylesheet" type="text/css"
+        href="chrome://mochikit/content/tests/SimpleTest/test.css" />
+
+  <script type="application/javascript"
+          src="chrome://mochikit/content/MochiKit/packed.js"></script>
+  <script type="application/javascript"
+          src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="application/javascript"
+          src="chrome://mochikit/content/tests/SimpleTest/EventUtils.js"></script>
+
+  <script type="application/javascript"
+          src="chrome://mochikit/content/a11y/accessible/common.js"></script>
+  <script type="application/javascript"
+          src="chrome://mochikit/content/a11y/accessible/events.js"></script>
+
+  <script type="application/javascript">
+    /**
+     * Checker for invokers.
+     */
+    function actionChecker(aDescription)
+    {
+      this.check = function actionChecker_check(aEvent)
+      {
+        var target = aEvent.accessible;
+        is(target.description, aDescription,
+           "Wrong description for " + prettyName(target));
+      }
+    }
+
+    var gFocusHandler = {
+      handleEvent: function gFocusHandler_handleEvent(aEvent) {
+        var elm = aEvent.target;
+        if (elm.nodeType != nsIDOMNode.ELEMENT_NODE)
+          return;
+
+        gTooltipElm.style.display = "block";
+
+        elm.setAttribute("aria-describedby", "tooltip");
+      }
+    };
+
+    var gBlurHandler = {
+      handleEvent: function gBlurHandler_handleEvent(aEvent) {
+        gTooltipElm.style.display = "none";
+
+        var elm = aEvent.target;
+        if (elm.nodeType == nsIDOMNode.ELEMENT_NODE)
+          elm.removeAttribute("aria-describedby");
+      }
+    };
+
+    /**
+     * Do tests.
+     */
+
+    // gA11yEventDumpID = "eventdump"; // debug stuff
+
+    var gQueue = null;
+
+    var gButtonElm = null;
+    var gTextboxElm = null;
+    var gTooltipElm = null;
+
+    function doTests()
+    {
+      gButtonElm = getNode("button");
+      gTextboxElm = getNode("textbox");
+      gTooltipElm = getNode("tooltip");
+
+      gButtonElm.addEventListener("focus", gFocusHandler, false);
+      gButtonElm.addEventListener("blur", gBlurHandler, false);
+      gTextboxElm.addEventListener("focus", gFocusHandler, false);
+      gTextboxElm.addEventListener("blur", gBlurHandler, false);
+
+      // The aria-describedby is changed on DOM focus. Accessible description
+      // should be updated when a11y focus is fired.
+      gQueue = new eventQueue(nsIAccessibleEvent.EVENT_FOCUS);
+      gQueue.onFinish = function()
+      {
+        gButtonElm.removeEventListener("focus", gFocusHandler, false);
+        gButtonElm.removeEventListener("blur", gBlurHandler, false);
+        gTextboxElm.removeEventListener("focus", gFocusHandler, false);
+        gTextboxElm.removeEventListener("blur", gBlurHandler, false);
+      }
+
+      var checker = new actionChecker("It's a tooltip");
+      gQueue.push(new synthFocus("button", checker));
+      gQueue.push(new synthTab("textbox", checker));
+
+      gQueue.invoke(); // Will call SimpleTest.finish();
+    }
+
+    SimpleTest.waitForExplicitFinish();
+    addA11yLoadEvent(doTests);
+  </script>
+</head>
+
+<body>
+
+  <a target="_blank"
+     href="https://bugzilla.mozilla.org/show_bug.cgi?id=520709"
+     title="mochitest to ensure name/description are updated on a11y focus if they were changed on DOM focus">
+    Mozilla Bug 520709
+  </a>
+  <p id="display"></p>
+  <div id="content" style="display: none"></div>
+  <pre id="test">
+  </pre>
+
+  <div id="tooltip" style="display: none" aria-hidden="true">It's a tooltip</div>
+  <button id="button">button</button>
+  <input id="textbox">
+
+  <div id="eventdump"></div>
+</body>
+</html>