Fix a few lingering bugs in BrowserAccessibilityManager and BrowserAccessibilityCocoa.

content/browser/accessibility/browser_accessibility_cocoa.mm

 // Copyright (c) 2011 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.
 
 #include <execinfo.h>
 
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 
 #include <map>
 
 #include "base/string16.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "content/browser/accessibility/browser_accessibility_manager.h"
 #include "content/common/content_client.h"
 #include "grit/webkit_strings.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebRect.h"
 
+// See http://openradar.appspot.com/9896491. This has been tested on 10.5,
+// 10.6, and 10.7.
+extern "C" void NSAccessibilityUnregisterUniqueIdForUIElement(id element);
+
 typedef WebAccessibility::IntAttribute IntAttribute;
 typedef WebAccessibility::StringAttribute StringAttribute;
 
 namespace {
 
 // Returns an autoreleased copy of the WebAccessibility's attribute.
 NSString* NSStringForStringAttribute(
     const std::map<StringAttribute, string16>& attributes,
     StringAttribute attribute) {
   std::map<StringAttribute, string16>::const_iterator iter =
@@ skipping 211 matching lines @@
   if ((self = [super init])) {
     browserAccessibility_ = accessibility;
     delegate_ = delegate;
   }
   return self;
 }
 
 // Deletes our associated BrowserAccessibilityMac.
 - (void)dealloc {
   if (browserAccessibility_) {
+    NSAccessibilityUnregisterUniqueIdForUIElement(self);
     delete browserAccessibility_;
     browserAccessibility_ = NULL;
   }
 
   [super dealloc];
 }
 
 // Returns an array of BrowserAccessibilityCocoa objects, representing the
 // accessibility children of this object.
 - (NSArray*)children {
@@ skipping 563 matching lines @@
   return ([self hash] == [object hash]);
 }
 
 - (NSUInteger)hash {
   // Potentially called during dealloc.
   if (!browserAccessibility_)
     return [super hash];
   return browserAccessibility_->renderer_id();
 }
 
+- (BOOL)accessibilityShouldUseUniqueId {
+  return YES;
+}
+
 @end