Add suborigin logic to url::Origin

url/origin.h

Index: url/origin.h
diff --git a/url/origin.h b/url/origin.h
index 89d81da5820823c94b42ef2ac26fc061bc95c0fb..beb24a05707e124a131d9843e7947f681d285100 100644
--- a/url/origin.h
+++ b/url/origin.h
@@ -116,19 +116,34 @@ class URL_EXPORT Origin {
   const std::string& host() const { return tuple_.host(); }
   uint16_t port() const { return tuple_.port(); }
 
+  // Note that an origin without a suborgin will return the empty string.
+  const std::string& suborigin() const { return suborigin_; }
+
   bool unique() const { return unique_; }
 
   // An ASCII serialization of the Origin as per Section 6.2 of RFC 6454, with
   // the addition that all Origins with a 'file' scheme serialize to "file://".
+  // If the Origin has a suborigin, it will be serialized per
+  // https://w3c.github.io/webappsec-suborigins/#serializing.
   std::string Serialize() const;
 
+  // Same as above, but ignores the suborigin component of the origin, if it
+  // exists, returning only the physical origin. For example, when
+  // SerializePhysicalOrigin() is called on the origin
+  // https-so://foobar.example.com, it will return https://example.com.
+  std::string SerializePhysicalOrigin() const;
+
   // Two Origins are "same-origin" if their schemes, hosts, and ports are exact
-  // matches; and neither is unique.
+  // matches; and neither is unique. If either of the origins have suborigins,
+  // the suborigins also must be exact matches.
   bool IsSameOriginWith(const Origin& other) const;
   bool operator==(const Origin& other) const {
     return IsSameOriginWith(other);
   }
 
+  // Same as above, but ignores suborigins if they exist.
+  bool IsSamePhysicalOriginWith(const Origin& other) const;

[michaeln, 2016/10/19 20:36:02]

Might be nice to have an Origin GetPhysicalOrigin() method too.

[jww, 2016/10/19 22:11:23]

Indeed. Per a suggestion from nasko@, I'm thinking it may make sense to replace
this with just:
   Origin GetPhysicalOrigin() const;
and then callers can use IsWithOriginWith() on the result of that value.

However, I'd rather do that in a follow-up CL, as I've just started thinking
about that possibility. Is that OK?

[jww, 2016/10/20 06:03:47]

Changed my mind and added it in this CL. I think it simplifies some
unnecessarily messy code.

+
   // Efficiently returns what GURL(Serialize()) would without re-parsing the
   // URL. This can be used for the (rare) times a GURL representation is needed
   // for an Origin.
@@ -152,11 +167,13 @@ class URL_EXPORT Origin {
 
   SchemeHostPort tuple_;
   bool unique_;
+  std::string suborigin_;
 };
 
 URL_EXPORT std::ostream& operator<<(std::ostream& out, const Origin& origin);
 
 URL_EXPORT bool IsSameOriginWith(const GURL& a, const GURL& b);
+URL_EXPORT bool IsSamePhysicalOriginWith(const GURL& a, const GURL& b);
 
 }  // namespace url