Revert of All changes to ui/webui/ from bookmarks CL that block other CLs

Revert of All changes to ui/webui/ from bookmarks CL that block other CLs (patchset #3 id:40001 of https://codereview.chromium.org/618133002/)

Reason for revert:
Broke testDropFromOutsideSource:
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%281%29/builds/32085
http://build.chromium.org/p/chromium.mac/builders/Mac%2010.7%20Tests%20%28dbg%29%282%29/builds/29382
http://build.chromium.org/p/chromium.linux/builders/Linux%20Tests%20%28dbg%29%281%29%2832%29/builds/6279
http://build.chromium.org/p/chromium.mac/builders/Mac%2010.6%20Tests%20%28dbg%29%282%29/builds/55520

Original issue's description:
> All changes to ui/webui/ from bookmarks CL that block other CLs
> 
> Already reviewed here: https://chromiumcodereview.appspot.com/543863002/
> 
> R=dbeam@chromium.org
> BUG=393873
> 
> Committed: https://crrev.com/5fa737de90b9f1ef3e359d9cf3d697cafd8e2d9f
> Cr-Commit-Position: refs/heads/master@{#297536}

TBR=dbeam@chromium.org,vitalyp@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=393873

[Nico, 2014-10-01 10:22:47]

Created Revert of All changes to ui/webui/ from bookmarks CL that block other
CLs

[commit-bot: I haz the power, 2014-10-01 10:23:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/620663004/1

[commit-bot: I haz the power, 2014-10-01 10:24:43]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-01 10:24:46]

Failed to apply patch for ui/webui/resources/js/cr/event_target.js:
While running git apply --index -3 -p1;
  error: patch failed: ui/webui/resources/js/cr/event_target.js:6
  Falling back to three-way merge...
  Applied patch to 'ui/webui/resources/js/cr/event_target.js' with conflicts.
  U ui/webui/resources/js/cr/event_target.js

Patch:       ui/webui/resources/js/cr/event_target.js
Index: ui/webui/resources/js/cr/event_target.js
diff --git a/ui/webui/resources/js/cr/event_target.js
b/ui/webui/resources/js/cr/event_target.js
index
6a73f1ff95a8b9d8a9adebfdadc797385b10763c..0d6fbd58adef11a886e548167ea7cd59456e0613
100644
--- a/ui/webui/resources/js/cr/event_target.js
+++ b/ui/webui/resources/js/cr/event_target.js
@@ -6,11 +6,6 @@
  * @fileoverview This contains an implementation of the EventTarget interface
  * as defined by DOM Level 2 Events.
  */
-
-/**
- * @typedef {EventListener|function(!Event):(boolean|undefined)}
- */
-var EventListenerType;
 
 cr.define('cr', function() {
 
@@ -28,8 +23,8 @@
     /**
      * Adds an event listener to the target.
      * @param {string} type The name of the event.
-     * @param {EventListenerType} handler The handler for the event. This is
-     *     called when the event is dispatched.
+     * @param {!Function|{handleEvent:Function}} handler The handler for the
+     *     event. This is called when the event is dispatched.
      */
     addEventListener: function(type, handler) {
       if (!this.listeners_)
@@ -46,7 +41,8 @@
     /**
      * Removes an event listener from the target.
      * @param {string} type The name of the event.
-     * @param {EventListenerType} handler The handler for the event.
+     * @param {!Function|{handleEvent:Function}} handler The handler for the
+     *     event.
      */
     removeEventListener: function(type, handler) {
       if (!this.listeners_)

[commit-bot: I haz the power, 2014-10-01 10:25:21]

The CQ bit was unchecked by commit-bot@chromium.org

[Dan Beam, 2014-10-27 15:38:38]

Nico: can we delete this?