Revert of HttpCache::Transaction layer allowing parallel validation

net/http/http_transaction_test_util.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NET_HTTP_HTTP_TRANSACTION_TEST_UTIL_H_
 #define NET_HTTP_HTTP_TRANSACTION_TEST_UTIL_H_
 
 #include "net/http/http_transaction.h"
 
 #include <stdint.h>
@@ skipping 262 matching lines @@
   int64_t sent_bytes_;
 
   // NetLog ID of the fake / non-existent underlying socket used by the
   // connection. Requires Start() be passed a NetLogWithSource with a real
   // NetLog to
   // be initialized.
   unsigned int socket_log_id_;
 
   bool done_reading_called_;
 
-  CompletionCallback callback_;  // used for pause and restart.
-
   base::WeakPtrFactory<MockNetworkTransaction> weak_factory_;
 
 };
 
 class MockNetworkLayer : public HttpTransactionFactory,
                          public base::SupportsWeakPtr<MockNetworkLayer> {
  public:
   MockNetworkLayer();
   ~MockNetworkLayer() override;
 
@@ skipping 56 matching lines @@
 
 //-----------------------------------------------------------------------------
 // helpers
 
 // read the transaction completely
 int ReadTransaction(HttpTransaction* trans, std::string* result);
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_TRANSACTION_TEST_UTIL_H_