Add the QuicRandom interface with a default implementation that is

net/quic/crypto/quic_random.cc

+// 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.
+
+#include "net/quic/crypto/quic_random.h"
+
+#include "base/logging.h"
+#include "base/memory/singleton.h"
+#include "crypto/random.h"
+
+namespace net {
+
+namespace {
+
+class DefaultRandom : public QuicRandom {
+ public:
+  static DefaultRandom* GetInstance();
+
+  // QuicRandom implementation
+  virtual void RandBytes(void* data, size_t len);
+  virtual uint64 RandUint64();
+  virtual void Reseed(const void* additional_entropy, size_t entropy_len);
+
+ private:
+  DefaultRandom();
+  virtual ~DefaultRandom() {}
+
+  friend struct DefaultSingletonTraits<DefaultRandom>;
+  DISALLOW_COPY_AND_ASSIGN(DefaultRandom);
+};
+
+DefaultRandom* DefaultRandom::GetInstance() {
+  return Singleton<DefaultRandom>::get();
+}
+
+void DefaultRandom::RandBytes(void* data, size_t len) {
+  crypto::RandBytes(data, len);
+}
+
+uint64 DefaultRandom::RandUint64() {
+  uint64 value;
+  RandBytes(&value, sizeof(value));
+  return value;
+}
+
+void DefaultRandom::Reseed(const void* additional_entropy, size_t entropy_len) {
+  // No such function exists in crypto/random.h.
+}
+
+DefaultRandom::DefaultRandom() {
+}
+
+}  // namespace
+
+// static
+QuicRandom* QuicRandom::GetInstance() {
+  return DefaultRandom::GetInstance();
+}
+
+}  // namespace net