Share Custom Element registration contexts between related documents.

Source/core/xml/DOMParser.cpp

Index: Source/core/xml/DOMParser.cpp
diff --git a/Source/core/xml/DOMParser.cpp b/Source/core/xml/DOMParser.cpp
index 561b34d57a9d504d94341dc9ff79cea96f1e5517..bbfbd111d7b2c68fa915198f59384d06176efdbd 100644
--- a/Source/core/xml/DOMParser.cpp
+++ b/Source/core/xml/DOMParser.cpp
@@ -19,6 +19,7 @@
 #include "config.h"
 #include "core/xml/DOMParser.h"
 
+#include "core/dom/CustomElementRegistrationContextualizer.h"
 #include "core/dom/DOMImplementation.h"
 #include "core/dom/Document.h"
 #include <wtf/text/WTFString.h>
@@ -31,6 +32,7 @@ PassRefPtr<Document> DOMParser::parseFromString(const String& str, const String&
         return 0;
 
     RefPtr<Document> doc = DOMImplementation::createDocument(contentType, 0, KURL(), false);
+    CustomElementRegistrationContextualizer::didCreateDocument(CustomElementRegistrationContextualizer::DOMParser_parseFromString, doc.get());
     doc->setContent(str);
     return doc.release();
 }