Teach URLRequest about initiator checks for First-Party-Only cookies.

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 f685cf76e7bb23fe2c0f93b28c687cd61cacc71a..6eb7961d25161bd280d93164e6f79451c1c9bf99 100644
--- a/net/url_request/url_request.h
+++ b/net/url_request/url_request.h
@@ -42,6 +42,10 @@ class StackTrace;
 }  // namespace debug
 }  // namespace base
 
+namespace url {
+class Origin;
+}
+
 namespace net {
 
 class ChunkedUploadDataStream;
@@ -282,12 +286,20 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
   }
   void set_first_party_url_policy(FirstPartyURLPolicy first_party_url_policy);
 
+  // The origin of the context which initiated the request.
+  const url::Origin initiator() const { return initiator_; }

[mmenke, 2015/10/21 15:36:38]

const url::Origin&

[mmenke, 2015/10/21 15:36:38]

I'm concerned that I have no idea what the difference between initiator and
first_party_for_cookies is, and the code here has no pointers to definitions for
either.  Can we add some pointers to RFCs?

[Mike West, 2015/10/22 13:17:02]

Done and done.

+  // This method may only be called before Start().
+  void set_initiator(const url::Origin& 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
   // should only be assigned an uppercase value.
   const std::string& method() const { return method_; }
   void set_method(const std::string& method);
 
+  // True if the request method is "safe" (per section 4.2.1 of RFC 7231).
+  bool is_safe_method() const;
+
   // The referrer URL for the request.  This header may actually be suppressed
   // from the underlying network request for security reasons (e.g., a HTTPS
   // URL will not be sent as the referrer for a HTTP request).  The referrer
@@ -759,6 +771,7 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
 
   std::vector<GURL> url_chain_;
   GURL first_party_for_cookies_;
+  url::Origin initiator_;
   GURL delegate_redirect_url_;
   std::string method_;  // "GET", "POST", etc. Should be all uppercase.
   std::string referrer_;