Make the request initiator Optional

url/origin.h

Index: url/origin.h
diff --git a/url/origin.h b/url/origin.h
index 273622edc8a0624901af12e2a8eac3d6e5a96b8c..fc14f633afb2b0dd4d53a25c6686976bd143b003 100644
--- a/url/origin.h
+++ b/url/origin.h
@@ -9,6 +9,7 @@
 
 #include <string>
 
+#include "base/memory/ref_counted.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_piece.h"
 #include "url/scheme_host_port.h"
@@ -102,7 +103,7 @@ class URL_EXPORT Origin {
       base::StringPiece host,
       uint16_t port);
 
-  ~Origin();
+  virtual ~Origin();
 
   // For unique origins, these return ("", "", 0).
   const std::string& scheme() const { return tuple_.scheme(); }
@@ -144,6 +145,20 @@ class URL_EXPORT Origin {
   bool unique_;
 };
 
+// A version of Origin that supports ref count and can be passed in a
+// scoped_refptr. This allows to specify a null Origin (as opposed to a unique
+// origin).
+class URL_EXPORT NullableOrigin : public Origin,

[Mike West, 2016/10/11 08:50:31]

This feels like a stopgap that we're doing just because it's a pain in the butt
to make `Origin` itself refcounted. I'm fine with that as a temporary measure
(and because you shouldn't have to do work I said I was going to do and then
didn't...), but I'd at least like a `TODO(mkwst)` here to remove
`NullableOrigin` as future cleanup.

+                                  public base::RefCounted<NullableOrigin> {
+ public:
+  explicit NullableOrigin(const GURL& url);
+  NullableOrigin(const Origin& origin);
+
+ private:
+  friend base::RefCounted<NullableOrigin>;
+  ~NullableOrigin() override;
+};
+
 URL_EXPORT std::ostream& operator<<(std::ostream& out, const Origin& origin);
 
 URL_EXPORT bool IsSameOriginWith(const GURL& a, const GURL& b);