diff -r 000000000000 -r 6474c204b198 accessible/src/mac/Platform.mm
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/accessible/src/mac/Platform.mm	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,54 @@
+/* -*- Mode: Objective-C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#import <Cocoa/Cocoa.h>
+
+#include "Platform.h"
+
+#include "nsAppShell.h"
+
+namespace mozilla {
+namespace a11y {
+
+// Mac a11y whitelisting
+static bool sA11yShouldBeEnabled = false;
+
+bool
+ShouldA11yBeEnabled()
+{
+  EPlatformDisabledState disabledState = PlatformDisabledState();
+  return (disabledState == ePlatformIsForceEnabled) || ((disabledState == ePlatformIsEnabled) && sA11yShouldBeEnabled);
+}
+
+void
+PlatformInit()
+{
+}
+
+void
+PlatformShutdown()
+{
+}
+
+}
+}
+
+@interface GeckoNSApplication(a11y)
+-(void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute;
+@end
+
+@implementation GeckoNSApplication(a11y)
+
+-(void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute
+{
+  if ([attribute isEqualToString:@"AXEnhancedUserInterface"])
+    mozilla::a11y::sA11yShouldBeEnabled = ([value intValue] == 1);
+
+  return [super accessibilitySetValue:value forAttribute:attribute];
+}
+
+@end
+