Disable accessibility when VoiceOver is turned off.

chrome/browser/chrome_browser_application_mac.mm

Index: chrome/browser/chrome_browser_application_mac.mm
diff --git a/chrome/browser/chrome_browser_application_mac.mm b/chrome/browser/chrome_browser_application_mac.mm
index 71c0efa190c1416a113931e4365f2d96dd3cbde4..e3a8ff2835071e76f1d9c4ceed072c1ddee76bbd 100644
--- a/chrome/browser/chrome_browser_application_mac.mm
+++ b/chrome/browser/chrome_browser_application_mac.mm
@@ -538,9 +538,14 @@ void SwizzleInit() {
 }
 
 - (void)accessibilitySetValue:(id)value forAttribute:(NSString*)attribute {
-  if ([attribute isEqualToString:@"AXEnhancedUserInterface"] &&
-      [value intValue] == 1) {
-    content::BrowserAccessibilityState::GetInstance()->OnScreenReaderDetected();
+  // This is an undocument attribute that's set when VoiceOver is turned on/off.
+  if ([attribute isEqualToString:@"AXEnhancedUserInterface"]) {
+    content::BrowserAccessibilityState* accessibility_state =
+        content::BrowserAccessibilityState::GetInstance();
+    if ([value intValue] == 1)
+      accessibility_state->OnScreenReaderDetected();
+    else
+      accessibility_state->DisableAccessibility();
   }
   return [super accessibilitySetValue:value forAttribute:attribute];
 }