Have getChildNodes() take a ContainerNode in argument

Source/core/editing/WrapContentsInDummySpanCommand.cpp

Index: Source/core/editing/WrapContentsInDummySpanCommand.cpp
diff --git a/Source/core/editing/WrapContentsInDummySpanCommand.cpp b/Source/core/editing/WrapContentsInDummySpanCommand.cpp
index 25e8d3e2c31a732ef6df86c48b68ffdda07ac7ff..2a9f803b44a7a758a422c5bfc563c97e3968008e 100644
--- a/Source/core/editing/WrapContentsInDummySpanCommand.cpp
+++ b/Source/core/editing/WrapContentsInDummySpanCommand.cpp
@@ -41,9 +41,8 @@ WrapContentsInDummySpanCommand::WrapContentsInDummySpanCommand(PassRefPtrWillBeR
 
 void WrapContentsInDummySpanCommand::executeApply()
 {
-    WillBeHeapVector<RefPtrWillBeMember<Node> > children;
-    for (Node* child = m_element->firstChild(); child; child = child->nextSibling())
-        children.append(child);
+    NodeVector children;
+    getChildNodes(*m_element, children);
 
     size_t size = children.size();
     for (size_t i = 0; i < size; ++i)
@@ -66,9 +65,8 @@ void WrapContentsInDummySpanCommand::doUnapply()
     if (!m_dummySpan || !m_element->hasEditableStyle())
         return;
 
-    WillBeHeapVector<RefPtrWillBeMember<Node> > children;
-    for (Node* child = m_dummySpan->firstChild(); child; child = child->nextSibling())
-        children.append(child);
+    NodeVector children;
+    getChildNodes(*m_dummySpan, children);
 
     size_t size = children.size();
     for (size_t i = 0; i < size; ++i)