Have StyledMarkupSerializer work on the Composed tree

Source/core/editing/EditingStrategy.h

Index: Source/core/editing/EditingStrategy.h
diff --git a/Source/core/editing/EditingStrategy.h b/Source/core/editing/EditingStrategy.h
index d68f1af30f2ede7fba30c3d9f8aaa652ea349b23..6137e182b4c88e941a5f53e401f47c0cffb4de27 100644
--- a/Source/core/editing/EditingStrategy.h
+++ b/Source/core/editing/EditingStrategy.h
@@ -41,6 +41,9 @@ public:
     using PositionIteratorType = PositionIteratorAlgorithm<EditingInComposedTreeStrategy>;
     using PositionType = PositionAlgorithm<EditingInComposedTreeStrategy>;
 
+    // Returns true if |shadowHost| is considered as selection boundary.
+    static bool isSelectionBoundaryShadowHost(const Node* shadowHost);

[tkent, 2015/06/19 06:07:49]

The argument name is confusing. Because this function accepts any nodes, the
argument name should be |node|, and the comment should be "if |node| is a shadow
host and it is considered ...|.

In the function definition, the argument name is |node|.  it's confusing.

[hajimehoshi, 2015/06/19 06:26:51]

Done. (just removed)

+
     // Don't use |parentOrShadowHostNode()| in composed tree specific algorithm.
     // This function is provided here for sharing algorithm with
     // |TextIteratorAlgorithm|, which handles shadow tree within in