Avoid unnecessary copies of AccessibilityChildrenVector

Source/modules/accessibility/AXARIAGrid.cpp

Index: Source/modules/accessibility/AXARIAGrid.cpp
diff --git a/Source/modules/accessibility/AXARIAGrid.cpp b/Source/modules/accessibility/AXARIAGrid.cpp
index 2cf3193abb26a64eeaf4ffa5d2d4b7be5e69bc12..6fe06eba85ffad7792a6b939eee0c9c66782f0c4 100644
--- a/Source/modules/accessibility/AXARIAGrid.cpp
+++ b/Source/modules/accessibility/AXARIAGrid.cpp
@@ -107,7 +107,7 @@ void AXARIAGrid::addChildren()
 
             // The children of this non-row will contain all non-ignored elements (recursing to find them).
             // This allows the table to dive arbitrarily deep to find the rows.
-            AccessibilityChildrenVector children = child->children();
+            const AccessibilityChildrenVector& children = child->children();
             size_t length = children.size();
             for (size_t i = 0; i < length; ++i)
                 addTableCellChild(children[i].get(), appendedRows, columnCount);