[net/http auth] Use strings to identify authentication schemes.

net/http/http_auth_cache.cc

Index: net/http/http_auth_cache.cc
diff --git a/net/http/http_auth_cache.cc b/net/http/http_auth_cache.cc
index d76d3ed40cd5dd912a87938c13c5bebdef952c99..d3eec51a2caed7acc64342c3c14e420c8ffd6305 100644
--- a/net/http/http_auth_cache.cc
+++ b/net/http/http_auth_cache.cc
@@ -80,8 +80,9 @@ HttpAuthCache::~HttpAuthCache() {
 // Performance: O(n), where n is the number of realm entries.
 HttpAuthCache::Entry* HttpAuthCache::Lookup(const GURL& origin,
                                             const std::string& realm,
-                                            HttpAuth::Scheme scheme) {
+                                            const std::string& scheme) {
   CheckOriginIsValid(origin);
+  DCHECK(HttpAuth::IsValidNormalizedScheme(scheme));
 
   int entries_examined = 0;
   // Linear scan through the realm entries.
@@ -135,12 +136,13 @@ HttpAuthCache::Entry* HttpAuthCache::LookupByPath(const GURL& origin,
 
 HttpAuthCache::Entry* HttpAuthCache::Add(const GURL& origin,
                                          const std::string& realm,
-                                         HttpAuth::Scheme scheme,
+                                         const std::string& scheme,
                                          const std::string& auth_challenge,
                                          const AuthCredentials& credentials,
                                          const std::string& path) {
   CheckOriginIsValid(origin);
   CheckPathIsValid(path);
+  DCHECK(HttpAuth::IsValidNormalizedScheme(scheme));
 
   base::TimeTicks now = base::TimeTicks::Now();
 
@@ -189,10 +191,7 @@ void HttpAuthCache::Entry::UpdateStaleChallenge(
   nonce_count_ = 1;
 }
 
-HttpAuthCache::Entry::Entry()
-    : scheme_(HttpAuth::AUTH_SCHEME_MAX),
-      nonce_count_(0) {
-}
+HttpAuthCache::Entry::Entry() : nonce_count_(0) {}
 
 void HttpAuthCache::Entry::AddPath(const std::string& path) {
   std::string parent_dir = GetParentDirectory(path);
@@ -235,8 +234,9 @@ bool HttpAuthCache::Entry::HasEnclosingPath(const std::string& dir,
 
 bool HttpAuthCache::Remove(const GURL& origin,
                            const std::string& realm,
-                           HttpAuth::Scheme scheme,
+                           const std::string& scheme,
                            const AuthCredentials& credentials) {
+  DCHECK(HttpAuth::IsValidNormalizedScheme(scheme));
   for (EntryList::iterator it = entries_.begin(); it != entries_.end(); ++it) {
     if (it->origin() == origin && it->realm() == realm &&
         it->scheme() == scheme) {
@@ -256,8 +256,9 @@ void HttpAuthCache::Clear() {
 
 bool HttpAuthCache::UpdateStaleChallenge(const GURL& origin,
                                          const std::string& realm,
-                                         HttpAuth::Scheme scheme,
+                                         const std::string& scheme,
                                          const std::string& auth_challenge) {
+  DCHECK(HttpAuth::IsValidNormalizedScheme(scheme));
   HttpAuthCache::Entry* entry = Lookup(origin, realm, scheme);
   if (!entry)
     return false;