Remove unused ShadowRootUsageOriginType enum

Source/core/dom/shadow/ShadowRoot.cpp

Index: Source/core/dom/shadow/ShadowRoot.cpp
diff --git a/Source/core/dom/shadow/ShadowRoot.cpp b/Source/core/dom/shadow/ShadowRoot.cpp
index 8a2517afc4494b9253749b77e3c08ddc3eb89c09..c781db09eb017b6ff29737f52bc90e334661e05c 100644
--- a/Source/core/dom/shadow/ShadowRoot.cpp
+++ b/Source/core/dom/shadow/ShadowRoot.cpp
@@ -50,12 +50,6 @@ struct SameSizeAsShadowRoot : public DocumentFragment, public TreeScope, public
 
 COMPILE_ASSERT(sizeof(ShadowRoot) == sizeof(SameSizeAsShadowRoot), shadowroot_should_stay_small);
 
-enum ShadowRootUsageOriginType {
-    ShadowRootUsageOriginWeb = 0,
-    ShadowRootUsageOriginNotWeb,
-    ShadowRootUsageOriginMax
-};
-
 ShadowRoot::ShadowRoot(Document& document, ShadowRootType type)
     : DocumentFragment(0, CreateShadowRoot)
     , TreeScope(*this, document)