[net/http auth] Make HttpAuthHandler challenge handling asynchronous.

net/http/http_auth_cache_unittest.cc

Index: net/http/http_auth_cache_unittest.cc
diff --git a/net/http/http_auth_cache_unittest.cc b/net/http/http_auth_cache_unittest.cc
index 036c6e3ffe04e665b4bf839b22bb3b30553023c9..1ab9e214435c5c7865a546af87b1d50116ef4372 100644
--- a/net/http/http_auth_cache_unittest.cc
+++ b/net/http/http_auth_cache_unittest.cc
@@ -36,8 +36,16 @@ class MockAuthHandler : public HttpAuthHandler {
   }
 
  protected:
-  int Init(const HttpAuthChallengeTokenizer& challenge) override {
-    return ERR_UNEXPECTED;  // Unused.
+  int InitializeFromChallengeInternal(
+      const HttpAuthChallengeTokenizer& challenge,
+      const HttpResponseInfo& response_with_challenge,
+      const CompletionCallback& callback) override {
+    return ERR_UNEXPECTED;
+  }
+
+  int InitializeFromCacheEntryInternal(
+      HttpAuthCache::Entry* cache_entry) override {
+    return ERR_UNEXPECTED;
   }
 
   int GenerateAuthTokenImpl(const AuthCredentials*,