Make CustomElementsRegistry lazily initialize script state.

third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.h

Index: third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.h
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.h b/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.h
index de7d2aaa98ccb722181a7683df4dfefd92421b95..1973aa24a8e76a0233cd78c8551d3af57079a7a2 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.h
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.h
@@ -29,9 +29,8 @@ class CORE_EXPORT CustomElementsRegistry final
     DEFINE_WRAPPERTYPEINFO();
 public:
     using Id = uint32_t;
-    static CustomElementsRegistry* create(
-        ScriptState*,
-        V0CustomElementRegistrationContext*);
+
+    static CustomElementsRegistry* create(V0CustomElementRegistrationContext*);
 
     void define(
         ScriptState*,
@@ -55,10 +54,15 @@ public:
 private:
     CustomElementsRegistry(const V0CustomElementRegistrationContext*);
 
+    void ensureScriptInitialized(ScriptState* scriptState)
+    {
+        if (State::ScriptNotInitialized == m_state)
+            initializeScript(scriptState);
+    }
+    void initializeScript(ScriptState*);
+
     // Retrieves the Map which, given a constructor, contains the id
     // of the definition; or given an id, contains the prototype.
-    // Returns true if the map was retrieved; false if the map was
-    // not initialized yet.
     v8::Local<v8::Map> idMap(ScriptState*);
 
     bool idForConstructor(
@@ -68,6 +72,12 @@ private:
 
     bool v0NameIsDefined(const AtomicString& name);
 
+    enum class State {

[esprehn, 2016/05/21 01:47:02]

We should be able to null check something instead, for example the handle this
is initializing.

+        ScriptNotInitialized,
+        ScriptInitialized
+    };
+    State m_state;
+
     Member<const V0CustomElementRegistrationContext> m_v0;
     HeapVector<Member<CustomElementDefinition>> m_definitions;
     HashSet<AtomicString> m_names;