Remove X-Retry-After support.

net/url_request/url_request_throttler_entry.h

Index: net/url_request/url_request_throttler_entry.h
diff --git a/net/url_request/url_request_throttler_entry.h b/net/url_request/url_request_throttler_entry.h
index 8a2589b1c6ca0192068449c1c46e6ca992d46e47..f7bfd15f280be349accec78bc6f2f3eee93b5805 100644
--- a/net/url_request/url_request_throttler_entry.h
+++ b/net/url_request/url_request_throttler_entry.h
@@ -58,10 +58,6 @@ class NET_EXPORT URLRequestThrottlerEntry
   // Time after which the entry is considered outdated.
   static const int kDefaultEntryLifetimeMs;
 
-  // Name of the header that servers can use to ask clients to delay their
-  // next request.
-  static const char kRetryHeaderName[];
-
   // Name of the header that sites can use to opt out of exponential back-off
   // throttling.
   static const char kExponentialThrottlingHeader[];
@@ -118,9 +114,6 @@ class NET_EXPORT URLRequestThrottlerEntry
   // Equivalent to TimeTicks::Now(), virtual to be mockable for testing purpose.
   virtual base::TimeTicks ImplGetTimeNow() const;
 
-  // Used internally to increase release time following a retry-after header.
-  void HandleCustomRetryAfter(const std::string& header_value);
-
   // Used internally to handle the opt-out header.
   void HandleThrottlingHeader(const std::string& header_value,
                               const std::string& host);