Revert of Apply Referrer-Policy header when following redirects

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 85eb2e4ead2f7c053ae1d0277db8d0e4733bb2db..97cf291eb25b6d923d1adf933f5e7ab73b131f4f 100644
--- a/net/url_request/url_request.h
+++ b/net/url_request/url_request.h
@@ -81,31 +81,27 @@
                                            NetworkDelegate* network_delegate,
                                            const std::string& scheme);
 
-  // A ReferrerPolicy for the request can be set with
-  // set_referrer_policy() and controls the contents of the Referer
-  // header when URLRequest follows server redirects.
+  // Referrer policies (see set_referrer_policy): During server redirects, the
+  // referrer header might be cleared, if the protocol changes from HTTPS to
+  // HTTP. This is the default behavior of URLRequest, corresponding to
+  // CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE. Alternatively, the
+  // referrer policy can be set to strip the referrer down to an origin upon
+  // cross-origin navigation (ORIGIN_ONLY_ON_TRANSITION_CROSS_ORIGIN), or
+  // never change the referrer header (NEVER_CLEAR_REFERRER). Embedders will
+  // want to use these options when implementing referrer policy support
+  // (https://w3c.github.io/webappsec/specs/referrer-policy/).
+  //
+  // REDUCE_REFERRER_GRANULARITY_ON_TRANSITION_CROSS_ORIGIN is a slight variant
+  // on CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE: If the request
+  // downgrades from HTTPS to HTTP, the referrer will be cleared. If the request
+  // transitions cross-origin (but does not downgrade), the referrer's
+  // granularity will be reduced (currently stripped down to an origin rather
+  // than a full URL). Same-origin requests will send the full referrer.
   enum ReferrerPolicy {
-    // Clear the referrer header if the protocol changes from HTTPS to
-    // HTTP. This is the default behavior of URLRequest.
     CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE,
-    // A slight variant on
-    // CLEAR_REFERRER_ON_TRANSITION_FROM_SECURE_TO_INSECURE: If the
-    // request downgrades from HTTPS to HTTP, the referrer will be
-    // cleared. If the request transitions cross-origin (but does not
-    // downgrade), the referrer's granularity will be reduced (currently
-    // stripped down to an origin rather than a full URL). Same-origin
-    // requests will send the full referrer.
     REDUCE_REFERRER_GRANULARITY_ON_TRANSITION_CROSS_ORIGIN,
-    // Strip the referrer down to an origin upon cross-origin navigation.
     ORIGIN_ONLY_ON_TRANSITION_CROSS_ORIGIN,
-    // Never change the referrer.
     NEVER_CLEAR_REFERRER,
-    // Strip the referrer down to the origin regardless of the redirect
-    // location.
-    ORIGIN,
-    // Always clear the referrer regardless of the redirect location.
-    NO_REFERRER,
-    MAX_REFERRER_POLICY
   };
 
   // First-party URL redirect policy: During server redirects, the first-party