Change a bool type to an enum type in constructor argument of SpaceSplitString.

Source/core/dom/SpaceSplitString.h

Index: Source/core/dom/SpaceSplitString.h
diff --git a/Source/core/dom/SpaceSplitString.h b/Source/core/dom/SpaceSplitString.h
index c5f47adb6c6173cd23969dcff3e9af3013490683..7763c0ff7b8751acb3fe41148e5f00f95a4dd89e 100644
--- a/Source/core/dom/SpaceSplitString.h
+++ b/Source/core/dom/SpaceSplitString.h
@@ -29,12 +29,13 @@ namespace blink {
 
 class SpaceSplitString {
 public:
+    enum CaseFolding { ShouldNotFoldCase, ShouldFoldCase };
     SpaceSplitString() { }
-    SpaceSplitString(const AtomicString& string, bool shouldFoldCase) { set(string, shouldFoldCase); }
+    SpaceSplitString(const AtomicString& string, CaseFolding caseFolding) { set(string, caseFolding); }
 
     bool operator!=(const SpaceSplitString& other) const { return m_data != other.m_data; }
 
-    void set(const AtomicString&, bool shouldFoldCase);
+    void set(const AtomicString&, CaseFolding);
     void clear() { m_data.clear(); }
 
     bool contains(const AtomicString& string) const { return m_data && m_data->contains(string); }