Use tighter typing in editing/

Source/core/editing/CompositeEditCommand.cpp

Index: Source/core/editing/CompositeEditCommand.cpp
diff --git a/Source/core/editing/CompositeEditCommand.cpp b/Source/core/editing/CompositeEditCommand.cpp
index f3264f2ffd7c61467e4cd5cbc7e9106c5cbcdf69..91def139b96b2100826b2855796985bc2901454b 100644
--- a/Source/core/editing/CompositeEditCommand.cpp
+++ b/Source/core/editing/CompositeEditCommand.cpp
@@ -64,6 +64,7 @@
 #include "core/events/ScopedEventQueue.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLElement.h"
+#include "core/html/HTMLSpanElement.h"
 #include "core/rendering/InlineTextBox.h"
 #include "core/rendering/RenderBlock.h"
 #include "core/rendering/RenderListItem.h"
@@ -540,7 +541,7 @@ Position CompositeEditCommand::positionOutsideTabSpan(const Position& pos)
         return positionInParentAfterNode(*pos.anchorNode());
     }
 
-    Node* tabSpan = tabSpanNode(pos.containerNode());
+    HTMLSpanElement* tabSpan = tabSpanElement(pos.containerNode());
     ASSERT(tabSpan);
 
     if (pos.offsetInContainerNode() <= caretMinOffset(pos.containerNode()))