NOT FOR REVIEW. ax tree focus with debugging

content/browser/renderer_host/render_widget_host_view_mac.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 "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 #include <stdint.h>
@@ skipping 2811 matching lines @@
   } else {
     return NSNotFound;
   }
 }
 
 - (id)accessibilityFocusedUIElement {
   BrowserAccessibilityManager* manager =
       renderWidgetHostView_->render_widget_host_
           ->GetRootBrowserAccessibilityManager();
   if (manager) {
-    BrowserAccessibility* focused_item = manager->GetFocus(NULL);
+    BrowserAccessibility* focused_item = manager->GetFocus();
     DCHECK(focused_item);
     if (focused_item) {
       BrowserAccessibilityCocoa* focused_item_cocoa =
           focused_item->ToBrowserAccessibilityCocoa();
       DCHECK(focused_item_cocoa);
       if (focused_item_cocoa)
         return focused_item_cocoa;
     }
   }
   return [super accessibilityFocusedUIElement];
@@ skipping 602 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end