Implement custom element construction and some 'define' checks

third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp

Index: third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
index acb4cfcd292594344964e315ca59425eaed2fd62..ca410ef58a8a9013af839fbca1ad794c770e9219 100644
--- a/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalDOMWindow.cpp
@@ -1324,8 +1324,10 @@ void LocalDOMWindow::cancelIdleCallback(int id)
 
 CustomElementsRegistry* LocalDOMWindow::customElements() const
 {
-    if (!m_customElements)
-        m_customElements = CustomElementsRegistry::create();
+    if (!m_customElements && frame()) {
+        ScriptState* scriptState = ScriptState::forMainWorld(frame());
+        m_customElements = CustomElementsRegistry::create(scriptState);
+    }
     return m_customElements.get();
 }