Cleanup <static_cast>: Switch to toFoo for Accessibility Objects.

Source/core/accessibility/AccessibilityARIAGridCell.cpp

Index: Source/core/accessibility/AccessibilityARIAGridCell.cpp
diff --git a/Source/core/accessibility/AccessibilityARIAGridCell.cpp b/Source/core/accessibility/AccessibilityARIAGridCell.cpp
index c2c17a238519083b331a5bf29d91470cfbe2c0f7..395194c8393e179030c2fa124b2f564687635896 100644
--- a/Source/core/accessibility/AccessibilityARIAGridCell.cpp
+++ b/Source/core/accessibility/AccessibilityARIAGridCell.cpp
@@ -77,7 +77,7 @@ void AccessibilityARIAGridCell::rowIndexRange(pair<unsigned, unsigned>& rowRange
 
     if (parent->isTableRow()) {
         // We already got a table row, use its API.
-        rowRange.first = static_cast<AccessibilityTableRow*>(parent)->rowIndex();
+        rowRange.first = toAccessibilityTableRow(parent)->rowIndex();
     } else if (parent->isAccessibilityTable()) {
         // We reached the parent table, so we need to inspect its
         // children to determine the row index for the cell in it.