Make Windows accessibility event firing aware of guest / child frames.

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>
 
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 
 #include <map>
 
@@ skipping 499 matching lines @@
       nil;
 }
 
 - (NSPoint)pointInScreen:(NSPoint)origin
                     size:(NSSize)size {
   if (!browserAccessibility_)
     return NSZeroPoint;
 
   // Get the delegate for the topmost BrowserAccessibilityManager, because
   // that's the only one that can convert points to their origin in the screen.
-  BrowserAccessibilityManager* manager = browserAccessibility_->manager();
-  BrowserAccessibility* root = manager->GetRoot();
-  while (root->GetParent())
-    root = root->GetParent()->manager()->GetRoot();
-  manager = root->manager();
-  BrowserAccessibilityDelegate* delegate = manager->delegate();
-
-  gfx::Rect bounds(origin.x, origin.y, size.width, size.height);
-  gfx::Point point = delegate->AccessibilityOriginInScreen(bounds);
-  return NSMakePoint(point.x(), point.y());
+  BrowserAccessibilityDelegate* delegate = GetDelegateFromRootManager();
+  if (delegate) {
+    gfx::Rect bounds(origin.x, origin.y, size.width, size.height);
+    gfx::Point point = delegate->AccessibilityOriginInScreen(bounds);
+    return NSMakePoint(point.x(), point.y());
+  } else {
+    return NSZeroPoint;
+  }
 }
 
 // Returns a string indicating the NSAccessibility role of this object.
 - (NSString*)role {
   ui::AXRole role = [self internalRole];
   if (role == ui::AX_ROLE_CANVAS &&
       browserAccessibility_->GetBoolAttribute(
           ui::AX_ATTR_CANVAS_HAS_FALLBACK)) {
     return NSAccessibilityGroupRole;
   }
@@ skipping 1001 matching lines @@
   if (!browserAccessibility_)
     return [super hash];
   return browserAccessibility_->GetId();
 }
 
 - (BOOL)accessibilityShouldUseUniqueId {
   return YES;
 }
 
 @end
-