Convert first letter into a pseudo element.

Source/core/dom/Position.cpp

Index: Source/core/dom/Position.cpp
diff --git a/Source/core/dom/Position.cpp b/Source/core/dom/Position.cpp
index 8b60a7c1dcf271ada29ee545a853ae7e7583469b..f453d3be667ddd71d5e151bdcb99b164a4f9ab3b 100644
--- a/Source/core/dom/Position.cpp
+++ b/Source/core/dom/Position.cpp
@@ -85,7 +85,7 @@ Position::Position(PassRefPtrWillBeRawPtr<Node> anchorNode, LegacyEditingOffset
     , m_anchorType(anchorTypeForLegacyEditingPosition(m_anchorNode.get(), m_offset))
     , m_isLegacyEditingPosition(true)
 {
-    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());
+    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement() || m_anchorNode->isFirstLetterPseudoElement());
 }
 
 Position::Position(PassRefPtrWillBeRawPtr<Node> anchorNode, AnchorType anchorType)
@@ -94,7 +94,7 @@ Position::Position(PassRefPtrWillBeRawPtr<Node> anchorNode, AnchorType anchorTyp
     , m_anchorType(anchorType)
     , m_isLegacyEditingPosition(false)
 {
-    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());
+    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement() || m_anchorNode->isFirstLetterPseudoElement());
 
     ASSERT(anchorType != PositionIsOffsetInAnchor);
     ASSERT(!((anchorType == PositionIsBeforeChildren || anchorType == PositionIsAfterChildren)
@@ -107,7 +107,7 @@ Position::Position(PassRefPtrWillBeRawPtr<Node> anchorNode, int offset, AnchorTy
     , m_anchorType(anchorType)
     , m_isLegacyEditingPosition(false)
 {
-    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement());
+    ASSERT(!m_anchorNode || !m_anchorNode->isPseudoElement() || m_anchorNode->isFirstLetterPseudoElement());
 
     ASSERT(anchorType == PositionIsOffsetInAnchor);
 }