Avoid unnecessary copies of AccessibilityChildrenVector

Source/modules/accessibility/AXTable.cpp

 /*
  * Copyright (C) 2008 Apple 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 476 matching lines @@
 
 void AXTable::cells(AXObject::AccessibilityChildrenVector& cells)
 {
     if (!m_renderer)
         return;
 
     updateChildrenIfNecessary();
 
     int numRows = m_rows.size();
     for (int row = 0; row < numRows; ++row) {
-        AccessibilityChildrenVector rowChildren = m_rows[row]->children();
-        cells.appendVector(rowChildren);
+        cells.appendVector(m_rows[row]->children());
     }
 }
 
 unsigned AXTable::columnCount()
 {
     updateChildrenIfNecessary();
 
     return m_columns.size();
 }
 
 unsigned AXTable::rowCount()
 {
     updateChildrenIfNecessary();
 
     return m_rows.size();
 }
 
 AXTableCell* AXTable::cellForColumnAndRow(unsigned column, unsigned row)
 {
     updateChildrenIfNecessary();
     if (column >= columnCount() || row >= rowCount())
         return 0;
 
     // Iterate backwards through the rows in case the desired cell has a rowspan and exists in a previous row.
     for (unsigned rowIndexCounter = row + 1; rowIndexCounter > 0; --rowIndexCounter) {
         unsigned rowIndex = rowIndexCounter - 1;
-        AccessibilityChildrenVector children = m_rows[rowIndex]->children();
+        const AccessibilityChildrenVector& children = m_rows[rowIndex]->children();
         // Since some cells may have colspans, we have to check the actual range of each
         // cell to determine which is the right one.
         for (unsigned colIndexCounter = std::min(static_cast<unsigned>(children.size()), column + 1); colIndexCounter > 0; --colIndexCounter) {
             unsigned colIndex = colIndexCounter - 1;
             AXObject* child = children[colIndex].get();
 
             if (!child->isTableCell())
                 continue;
 
             pair<unsigned, unsigned> columnRange;
@@ skipping 51 matching lines @@
     }
 
     // try the standard
     if (title.isEmpty())
         title = AXLayoutObject::title(mode);
 
     return title;
 }
 
 } // namespace blink