Add url::Origin::GetURL() to convert Origins to URLs without reparsing

url/scheme_host_port.h

Index: url/scheme_host_port.h
diff --git a/url/scheme_host_port.h b/url/scheme_host_port.h
index 47a9041e2afd8e1db1b92654b0d72cfddef9bdd4..58d0212e2d18b3583a00b18ef99a5c9a59d28348 100644
--- a/url/scheme_host_port.h
+++ b/url/scheme_host_port.h
@@ -111,6 +111,10 @@ class URL_EXPORT SchemeHostPort {
   // serialized as a unique Origin.
   std::string Serialize() const;
 
+  // Efficiently returns what GURL(Serialize()) would return, without needing to
+  // re-parse the URL.
+  GURL GetURL() const;
+
   // Two SchemeHostPort objects are "equal" iff their schemes, hosts, and ports
   // are exact matches.
   //