Rename childNodeCount() / childNode() methods for clarity

Source/core/editing/InsertParagraphSeparatorCommand.cpp

Index: Source/core/editing/InsertParagraphSeparatorCommand.cpp
diff --git a/Source/core/editing/InsertParagraphSeparatorCommand.cpp b/Source/core/editing/InsertParagraphSeparatorCommand.cpp
index 9ad4234a4bb728f8321eee2790bc2d580f6bb79a..24deac4a9c73a90c18703681d5b3508a7667f138 100644
--- a/Source/core/editing/InsertParagraphSeparatorCommand.cpp
+++ b/Source/core/editing/InsertParagraphSeparatorCommand.cpp
@@ -280,7 +280,7 @@ void InsertParagraphSeparatorCommand::doApply()
             refNode = startBlock->firstChild();
         }
         else if (insertionPosition.deprecatedNode() == startBlock && nestNewBlock) {
-            refNode = startBlock->childNode(insertionPosition.deprecatedEditingOffset());
+            refNode = startBlock->traverseToChildAt(insertionPosition.deprecatedEditingOffset());
             ASSERT(refNode); // must be true or we'd be in the end of block case
         } else
             refNode = insertionPosition.deprecatedNode();