Avoid unnecessary copies of AccessibilityChildrenVector

Source/modules/accessibility/AXNodeObject.cpp

 /*
 * Copyright (C) 2012, Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 1635 matching lines @@
 {
     if (!child)
         return;
 
     // If the parent is asking for this child's children, then either it's the first time (and clearing is a no-op),
     // or its visibility has changed. In the latter case, this child may have a stale child cached.
     // This can prevent aria-hidden changes from working correctly. Hence, whenever a parent is getting children, ensure data is not stale.
     child->clearChildren();
 
     if (child->accessibilityIsIgnored()) {
-        AccessibilityChildrenVector children = child->children();
+        const AccessibilityChildrenVector& children = child->children();
         size_t length = children.size();
         for (size_t i = 0; i < length; ++i)
             m_children.insert(index + i, children[i]);
     } else {
         ASSERT(child->parentObject() == this);
         m_children.insert(index, child);
     }
 }
 
 bool AXNodeObject::canHaveChildren() const
@@ skipping 325 matching lines @@
     float range = maxValueForRange() - minValueForRange();
     float value = valueForRange();
 
     value += range * (percentChange / 100);
     setValue(String::number(value));
 
     axObjectCache()->postNotification(node(), AXObjectCacheImpl::AXValueChanged, true);
 }
 
 } // namespace blink