Improve QUIC's SentEntropyManagerTest and removing a test from

net/quic/quic_sent_entropy_manager.h

 // Copyright 2013 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.
 //
 // Manages the packet entropy calculation for both sent and received packets
 // for a connection.
 
 #ifndef NET_QUIC_QUIC_SENT_ENTROPY_MANAGER_H_
 #define NET_QUIC_QUIC_SENT_ENTROPY_MANAGER_H_
 
 #include "net/base/linked_hash_map.h"
 #include "net/quic/quic_framer.h"
 #include "net/quic/quic_protocol.h"
 
 namespace net {
 
+namespace test {
+class QuicConnectionPeer;
+}  // namespace test
+
 // Records all sent packets by a connection to track the cumulative entropy of
 // sent packets.  It is used by the connection to validate an ack
 // frame sent by the peer as a preventive measure against the optimistic ack
 // attack.
 class NET_EXPORT_PRIVATE QuicSentEntropyManager {
  public:
   QuicSentEntropyManager();
   virtual ~QuicSentEntropyManager();
 
   // Record |entropy_hash| for sent packet corresponding to |sequence_number|.
   void RecordPacketEntropyHash(QuicPacketSequenceNumber sequence_number,
                                QuicPacketEntropyHash entropy_hash);
 
   QuicPacketEntropyHash EntropyHash(
       QuicPacketSequenceNumber sequence_number) const;
 
   // Returns true if |entropy_hash| matches the expected sent entropy hash
   // up to |sequence_number| removing sequence numbers from |missing_packets|.
   bool IsValidEntropy(QuicPacketSequenceNumber sequence_number,
                       const SequenceNumberSet& missing_packets,
                       QuicPacketEntropyHash entropy_hash) const;
 
   // Removes not required entries from |packets_entropy_| before
   // |sequence_number|.
   void ClearEntropyBefore(QuicPacketSequenceNumber sequence_number);
 
  private:
+  friend class test::QuicConnectionPeer;
+
   typedef linked_hash_map<QuicPacketSequenceNumber,
                           std::pair<QuicPacketEntropyHash,
                                QuicPacketEntropyHash> > SentEntropyMap;
 
   // Linked hash map from sequence numbers to the sent entropy hash up to the
   // sequence number in the key.
   SentEntropyMap packets_entropy_;
 
   // Cumulative hash of entropy of all sent packets.
   QuicPacketEntropyHash packets_entropy_hash_;
 
   DISALLOW_COPY_AND_ASSIGN(QuicSentEntropyManager);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_QUIC_SENT_ENTROPY_MANAGER_H_