Don't copy the security origin when creating a document

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

Index: third_party/WebKit/Source/core/dom/DOMImplementation.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMImplementation.cpp b/third_party/WebKit/Source/core/dom/DOMImplementation.cpp
index cd82533489e4fca2f77587bbc5ebe4d819e27721..a2b606037efbe4107243eed3dfb529a88d523aaf 100644
--- a/third_party/WebKit/Source/core/dom/DOMImplementation.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMImplementation.cpp
@@ -88,7 +88,7 @@ RawPtr<XMLDocument> DOMImplementation::createDocument(const AtomicString& namesp
         doc = XMLDocument::create(init);
     }
 
-    doc->setSecurityOrigin(document().getSecurityOrigin()->isolatedCopy());
+    doc->setSecurityOrigin(document().getSecurityOrigin());
     doc->setContextFeatures(document().contextFeatures());
 
     RawPtr<Node> documentElement = nullptr;
@@ -210,7 +210,7 @@ RawPtr<HTMLDocument> DOMImplementation::createHTMLDocument(const String& title)
         headElement->appendChild(titleElement);
         titleElement->appendChild(d->createTextNode(title), ASSERT_NO_EXCEPTION);
     }
-    d->setSecurityOrigin(document().getSecurityOrigin()->isolatedCopy());
+    d->setSecurityOrigin(document().getSecurityOrigin());
     d->setContextFeatures(document().contextFeatures());
     return d.release();
 }