Fix some minor typos related to the word "accessibility".

chrome/common/extensions/api/automation_internal.idl

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This is the implementation layer of the chrome.automation API, and is
 // essentially a translation of the internal accessibility tree update system
 // into an extension API.
 namespace automationInternal {
   dictionary Rect {
     long left;
@@ skipping 20 matching lines @@
     object? stringAttributes;
     long[] childIds;
   };
 
   dictionary AXTreeUpdate {
     // ID of the node, if any, which should be invalidated before the new data
     // is applied.
     long nodeIdToClear;
 
     // A vector of nodes to update according to the rules described in
-    // ui/accesibility/ax_tree_update.h.
+    // ui/accessibility/ax_tree_update.h.
     AXNodeData[] nodes;
   };
 
   // Data for an accessibility event and/or an atomic change to an accessibility
   // tree. See ui/accessibility/ax_tree_update.h for an extended explanation of
   // the tree update format.
   dictionary AXEventParams {
     // The process id of the renderer host.
     long processID;
 
@@ skipping 54 matching lines @@
                               object opt_args);
   };
 
   interface Events {
     // Fired when an accessibility event occurs
     static void onAccessibilityEvent(AXEventParams update);
 
     static void onAccessibilityTreeDestroyed(long processID, long routingID);
   };
 };