Add a new QuicFlagSaver class for saving/restoring the values of QUIC flags in tests.

net/quic/test_tools/quic_test_utils.h

 // Copyright (c) 2012 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.
 //
 // Common utilities for Quic tests
 
 #ifndef NET_QUIC_TEST_TOOLS_QUIC_TEST_UTILS_H_
 #define NET_QUIC_TEST_TOOLS_QUIC_TEST_UTILS_H_
 
 #include <stddef.h>
@@ skipping 197 matching lines @@
 // packet could not be created.
 QuicPacket* BuildUnsizedDataPacket(QuicFramer* framer,
                                    const QuicPacketHeader& header,
                                    const QuicFrames& frames);
 // Returns a QuicPacket that is owned by the caller, and of size |packet_size|.
 QuicPacket* BuildUnsizedDataPacket(QuicFramer* framer,
                                    const QuicPacketHeader& header,
                                    const QuicFrames& frames,
                                    size_t packet_size);
 
-template <typename SaveType>
-class ValueRestore {
+// When constructed, checks that all QUIC flags have their correct default
+// values and when destructed, restores those values.
+class QuicFlagSaver {
  public:
-  ValueRestore(SaveType* name, SaveType value) : name_(name), value_(*name) {
-    *name_ = value;
-  }
-  ~ValueRestore() { *name_ = value_; }
-
- private:
-  SaveType* name_;
-  SaveType value_;
-
-  DISALLOW_COPY_AND_ASSIGN(ValueRestore);
+  QuicFlagSaver();
+  ~QuicFlagSaver();
 };
 
 // Simple random number generator used to compute random numbers suitable
 // for pseudo-randomly dropping packets in tests.  It works by computing
 // the sha1 hash of the current seed, and using the first 64 bits as
 // the next random number, and the next seed.
 class SimpleRandom {
  public:
   SimpleRandom() : seed_(0) {}
 
@@ skipping 790 matching lines @@
     TestQuicSpdyServerSession** server_session);
 
 // Helper to generate client side stream ids, generalizes
 // kClientDataStreamId1 etc. above.
 QuicStreamId QuicClientDataStreamId(int i);
 
 }  // namespace test
 }  // namespace net
 
 #endif  // NET_QUIC_TEST_TOOLS_QUIC_TEST_UTILS_H_