Make the request initiator Optional

net/url_request/url_request.h

Index: net/url_request/url_request.h
diff --git a/net/url_request/url_request.h b/net/url_request/url_request.h
index 993afc97876f17179c82f0c80227be21347f11b8..e6c7d83889982fc49d9310fcb6ebe2fecdfaad3d 100644
--- a/net/url_request/url_request.h
+++ b/net/url_request/url_request.h
@@ -299,9 +299,9 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
   //
   // This value is used to perform the cross-origin check specified in Section
   // 4.3 of https://tools.ietf.org/html/draft-west-first-party-cookies.
-  const url::Origin& initiator() const { return initiator_; }
+  url::NullableOrigin* initiator() const { return initiator_.get(); }
   // This method may only be called before Start().
-  void set_initiator(const url::Origin& initiator);
+  void set_initiator(scoped_refptr<url::NullableOrigin> initiator);
 
   // The request method, as an uppercase string.  "GET" is the default value.
   // The request method may only be changed before Start() is called and
@@ -757,7 +757,7 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
 
   std::vector<GURL> url_chain_;
   GURL first_party_for_cookies_;
-  url::Origin initiator_;
+  scoped_refptr<url::NullableOrigin> initiator_;
   GURL delegate_redirect_url_;
   std::string method_;  // "GET", "POST", etc. Should be all uppercase.
   std::string referrer_;