Use tighter typing in editing: VisiblePosition & VisibleSelection

Source/core/editing/BreakBlockquoteCommand.cpp

Index: Source/core/editing/BreakBlockquoteCommand.cpp
diff --git a/Source/core/editing/BreakBlockquoteCommand.cpp b/Source/core/editing/BreakBlockquoteCommand.cpp
index cfebe0501651d52849a77c036a66c26bca45cb23..b49f5b9776958f55e2e59ce34f36fb87aca0ed6e 100644
--- a/Source/core/editing/BreakBlockquoteCommand.cpp
+++ b/Source/core/editing/BreakBlockquoteCommand.cpp
@@ -102,7 +102,7 @@ void BreakBlockquoteCommand::doApply()
         pos = pos.next();
 
     // Adjust the position so we don't split at the beginning of a quote.
-    while (isFirstVisiblePositionInNode(VisiblePosition(pos), enclosingNodeOfType(pos, isMailHTMLBlockquoteElement)))
+    while (isFirstVisiblePositionInNode(VisiblePosition(pos), toHTMLQuoteElement(enclosingNodeOfType(pos, isMailHTMLBlockquoteElement))))
         pos = pos.previous();
 
     // startNode is the first node that we need to move to the new blockquote.