Convert first letter into a pseudo element.

Source/core/dom/ElementRareData.cpp

Index: Source/core/dom/ElementRareData.cpp
diff --git a/Source/core/dom/ElementRareData.cpp b/Source/core/dom/ElementRareData.cpp
index cee844d6fa80131b208c516e4932db9ec35bae04..1a4bba1e75f34c2e4c242901fcce77651079bea2 100644
--- a/Source/core/dom/ElementRareData.cpp
+++ b/Source/core/dom/ElementRareData.cpp
@@ -39,7 +39,7 @@ struct SameSizeAsElementRareData : NodeRareData {
     short indices[2];
     LayoutSize sizeForResizing;
     IntSize scrollOffset;
-    void* pointers[13];
+    void* pointers[14];
 };
 
 CSSStyleDeclaration& ElementRareData::ensureInlineCSSStyleDeclaration(Element* ownerElement)
@@ -70,6 +70,7 @@ void ElementRareData::traceAfterDispatch(Visitor* visitor)
     visitor->trace(m_cssomWrapper);
     visitor->trace(m_generatedBefore);
     visitor->trace(m_generatedAfter);
+    visitor->trace(m_generatedFirstLetter);
     visitor->trace(m_backdrop);
     NodeRareData::traceAfterDispatch(visitor);
 }