Remove HttpAuth::Scheme enum in favor of a string.

net/http/http_auth.h

Index: net/http/http_auth.h
diff --git a/net/http/http_auth.h b/net/http/http_auth.h
index 364f933bcc388678e23fb042eec454bb6e3a131f..42042086820a59bac49174a2d5259eb27f62c846 100644
--- a/net/http/http_auth.h
+++ b/net/http/http_auth.h
@@ -87,15 +87,6 @@ class NET_EXPORT_PRIVATE HttpAuth {
     IDENT_SRC_DEFAULT_CREDENTIALS,
   };
 
-  enum Scheme {
-    AUTH_SCHEME_BASIC = 0,
-    AUTH_SCHEME_DIGEST,
-    AUTH_SCHEME_NTLM,
-    AUTH_SCHEME_NEGOTIATE,
-    AUTH_SCHEME_MOCK,
-    AUTH_SCHEME_MAX,
-  };
-
   // Helper structure used by HttpNetworkTransaction to track
   // the current identity being used for authorization.
   struct Identity {
@@ -118,9 +109,6 @@ class NET_EXPORT_PRIVATE HttpAuth {
   // messages.
   static std::string GetAuthTargetString(Target target);
 
-  // Returns a string representation of an authentication Scheme.
-  static const char* SchemeToString(Scheme scheme);
-
   // Iterate through the challenge headers, and pick the best one that
   // we support. Obtains the implementation class for handling the challenge,
   // and passes it back in |*handler|. If no supported challenge was found,
@@ -135,7 +123,7 @@ class NET_EXPORT_PRIVATE HttpAuth {
       const HttpResponseHeaders* headers,
       Target target,
       const GURL& origin,
-      const std::set<Scheme>& disabled_schemes,
+      const std::set<std::string>& disabled_schemes,
       const BoundNetLog& net_log,
       scoped_ptr<HttpAuthHandler>* handler);
 
@@ -164,7 +152,7 @@ class NET_EXPORT_PRIVATE HttpAuth {
       HttpAuthHandler* handler,
       const HttpResponseHeaders* headers,
       Target target,
-      const std::set<Scheme>& disabled_schemes,
+      const std::set<std::string>& disabled_schemes,
       std::string* challenge_used);
 
   // Breaks up a challenge string into the the auth scheme and parameter list,