Rename {Author,UserAgent}ShadowRoot to {Open,Closed}ShadowRoot.

Source/core/dom/shadow/ShadowRoot.h

Index: Source/core/dom/shadow/ShadowRoot.h
diff --git a/Source/core/dom/shadow/ShadowRoot.h b/Source/core/dom/shadow/ShadowRoot.h
index 40bea4b556baa3151579b6b714e48347db05e197..a4904f5195f4157b51cb1882eafe5b71576a59eb 100644
--- a/Source/core/dom/shadow/ShadowRoot.h
+++ b/Source/core/dom/shadow/ShadowRoot.h
@@ -53,8 +53,8 @@ public:
     // in several elements for a while.
     // See https://bugs.webkit.org/show_bug.cgi?id=77503 and related bugs.
     enum ShadowRootType {
-        UserAgentShadowRoot = 0,
-        AuthorShadowRoot
+        ClosedShadowRoot = 0,
+        OpenShadowRoot
     };
 
     static PassRefPtrWillBeRawPtr<ShadowRoot> create(Document& document, ShadowRootType type)
@@ -74,7 +74,7 @@ public:
     ShadowRoot* youngerShadowRoot() const { return prev(); }
 
     ShadowRoot* olderShadowRootForBindings() const;
-    bool shouldExposeToBindings() const { return type() == AuthorShadowRoot; }
+    bool shouldExposeToBindings() const { return type() == OpenShadowRoot; }
 
     bool isYoungest() const { return !youngerShadowRoot(); }
     bool isOldest() const { return !olderShadowRoot(); }