Make CanonicalCookie::Source() private.

net/cookies/canonical_cookie.h

Index: net/cookies/canonical_cookie.h
diff --git a/net/cookies/canonical_cookie.h b/net/cookies/canonical_cookie.h
index 00a2dd8d862799eabf0ad2d1ac6cc2c84a55df47..20e407b06ee3bca152ddbb76a9bb7bdf0485f03f 100644
--- a/net/cookies/canonical_cookie.h
+++ b/net/cookies/canonical_cookie.h
@@ -86,7 +86,6 @@ class NET_EXPORT CanonicalCookie {
                                                  CookieSameSite same_site,
                                                  CookiePriority priority);
 
-  const GURL& Source() const { return source_; }
   const std::string& Name() const { return name_; }
   const std::string& Value() const { return value_; }
   const std::string& Domain() const { return domain_; }
@@ -198,6 +197,8 @@ class NET_EXPORT CanonicalCookie {
                                   const GURL& url,
                                   const ParsedCookie& parsed_cookie);
 
+  const GURL& Source() const { return source_; }
+
   // The source member of a canonical cookie is the origin of the URL that tried
   // to set this cookie.  This field is not persistent though; its only used in
   // the in-tab cookies dialog to show the user the source URL. This is used for