Use tighter typing in editing: SimplifyMarkupCommand & TextIterator

Source/core/editing/TextInsertionBaseCommand.cpp

Index: Source/core/editing/TextInsertionBaseCommand.cpp
diff --git a/Source/core/editing/TextInsertionBaseCommand.cpp b/Source/core/editing/TextInsertionBaseCommand.cpp
index 0ad5828fd3b0fdcba7558a0c1e7797774c4cb1d0..690f71fbed7c35c7813b0f6574afe23d56fa502d 100644
--- a/Source/core/editing/TextInsertionBaseCommand.cpp
+++ b/Source/core/editing/TextInsertionBaseCommand.cpp
@@ -73,12 +73,12 @@ String dispatchBeforeTextInsertedEvent(const String& text, const VisibleSelectio
 
 bool canAppendNewLineFeedToSelection(const VisibleSelection& selection)
 {
-    Node* node = selection.rootEditableElement();
-    if (!node)
+    Element* element = selection.rootEditableElement();
+    if (!element)
         return false;
 
     RefPtrWillBeRawPtr<BeforeTextInsertedEvent> event = BeforeTextInsertedEvent::create(String("\n"));
-    node->dispatchEvent(event, IGNORE_EXCEPTION);
+    element->dispatchEvent(event, IGNORE_EXCEPTION);
     return event->text().length();
 }