MacViews a11y: Sync VoiceOver cursor with keyboard focus.

content/browser/accessibility/browser_accessibility_cocoa.mm

 // Copyright (c) 2012 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>
 #include <stddef.h>
 #include <stdint.h>
 
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 
@@ skipping 88 matching lines @@
   int32_t node_id;
   int offset;
   ui::AXTextAffinity affinity;
 };
 
 // VoiceOver uses -1 to mean "no limit" for AXResultsLimit.
 const int kAXResultsLimitNoLimit = -1;
 
 extern "C" {
 
-// See http://openradar.appspot.com/9896491. This SPI has been tested on 10.5,
-// 10.6, and 10.7. It allows accessibility clients to observe events posted on
-// this object.
-void NSAccessibilityUnregisterUniqueIdForUIElement(id element);
-
 // The following are private accessibility APIs required for cursor navigation
 // and text selection. VoiceOver started relying on them in Mac OS X 10.11.
 #if !defined(MAC_OS_X_VERSION_10_11) || \
     MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_11
 
 AXTextMarkerRef AXTextMarkerCreate(CFAllocatorRef allocator,
                                    const UInt8* bytes,
                                    CFIndex length);
 
 const UInt8* AXTextMarkerGetBytePtr(AXTextMarkerRef text_marker);
@@ skipping 479 matching lines @@
   dict = nil;
 }
 
 - (instancetype)initWithObject:(BrowserAccessibility*)accessibility {
   if ((self = [super init]))
     browserAccessibility_ = accessibility;
   return self;
 }
 
 - (void)detach {
-  if (browserAccessibility_)
-    NSAccessibilityUnregisterUniqueIdForUIElement(self);
+  if (!browserAccessibility_)
+    return;
+  NSAccessibilityPostNotification(
+      self, NSAccessibilityUIElementDestroyedNotification);
   browserAccessibility_ = nullptr;
 }
 
 - (NSString*)accessKey {
   if (![self instanceActive])
     return nil;
   return NSStringForStringAttribute(
       browserAccessibility_, ui::AX_ATTR_ACCESS_KEY);
 }
 
@@ skipping 2248 matching lines @@
   return ([self hash] == [object hash]);
 }
 
 - (NSUInteger)hash {
   // Potentially called during dealloc.
   if (![self instanceActive])
     return [super hash];
   return browserAccessibility_->GetId();
 }
 
-- (BOOL)accessibilityShouldUseUniqueId {
+- (BOOL)accessibilityNotifiesWhenDestroyed {
+  // Indicate that BrowserAccessibilityCocoa will post a notification when it's
+  // destroyed (see - detach). This allows VoiceOver to do some internal

[tapted, 2016/10/04 08:17:39]

nit: -detach (no space)

[Patti Lor, 2016/10/05 05:47:23]

Done.

+  // things more efficiently.
   return YES;
 }
 
 @end