Use c++11 range loops in accessibility

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 a543b9608c14715c87f86d80f0a918796eeea6af..0d3349ac670a6ba9aded0d360c8b434d8106ede8 100644
--- a/Source/modules/accessibility/AXARIAGrid.cpp
+++ b/Source/modules/accessibility/AXARIAGrid.cpp
@@ -107,10 +107,8 @@ 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.
-            const AccessibilityChildrenVector& children = child->children();
-            size_t length = children.size();
-            for (size_t i = 0; i < length; ++i)
-                addTableCellChild(children[i].get(), appendedRows, columnCount);
+            for (const auto& childObject : child->children())
+                addTableCellChild(childObject.get(), appendedRows, columnCount);
         }
     }