accessibility: Simpler code using ChildAtIndex() method.

content/browser/accessibility/browser_accessibility.cc

 // 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/accessibility/browser_accessibility.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
@@ skipping 112 matching lines @@
 uint32 BrowserAccessibility::InternalChildCount() const {
   if (!node_ || !manager_)
     return 0;
   return static_cast<uint32>(node_->child_count());
 }
 
 BrowserAccessibility* BrowserAccessibility::InternalGetChild(
     uint32 child_index) const {
   if (!node_ || !manager_)
     return NULL;
-  return manager_->GetFromAXNode(node_->children()[child_index]);
+  return manager_->GetFromAXNode(node_->ChildAtIndex(child_index));
 }
 
 BrowserAccessibility* BrowserAccessibility::GetParent() const {
   if (!node_ || !manager_)
     return NULL;
   ui::AXNode* parent = node_->parent();
   if (parent)
     return manager_->GetFromAXNode(parent);
 
   if (!manager_->delegate())
@@ skipping 565 matching lines @@
       }
       need_to_offset_web_area = true;
     }
     parent = parent->GetParentForBoundsCalculation();
   }
 
   return bounds;
 }
 
 }  // namespace content