binding: Changes the association among global-proxy/global/window-instance.

third_party/WebKit/Source/core/dom/Document.cpp

Index: third_party/WebKit/Source/core/dom/Document.cpp
diff --git a/third_party/WebKit/Source/core/dom/Document.cpp b/third_party/WebKit/Source/core/dom/Document.cpp
index 03a65cf6a6ec13f79de3710a15377b2db0ef2274..37178b2943fee552d0cfd3da7a05ed7a4b19066f 100644
--- a/third_party/WebKit/Source/core/dom/Document.cpp
+++ b/third_party/WebKit/Source/core/dom/Document.cpp
@@ -5211,6 +5211,13 @@ DocumentNameCollection* Document::documentNamedItems(const AtomicString& name) {
                                                         name);
 }
 
+LocalDOMWindow* Document::defaultView() const {
+  // The HTML spec requires to return null if the document is detached from a
+  // frame.  However, |m_domWindow| is not cleared on the detachment.  So, we
+  // need to check |m_frame| to tell whether the document is attached or not.
+  return m_frame ? m_domWindow : nullptr;
+}
+
 void Document::finishedParsing() {
   DCHECK(!scriptableDocumentParser() || !m_parser->isParsing());
   DCHECK(!scriptableDocumentParser() || m_readyState != Loading);