Move PRNG from BWE test framework to webrtc/test.

webrtc/modules/remote_bitrate_estimator/test/bwe_test.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 929 matching lines @@
 // Following functions are used for randomizing TCP file size and
 // starting time, used on 5.7 RunMultipleShortTcpFairness.
 // They are pseudo-random generators, creating always the same
 // value sequence for a given Random seed.
 
 std::vector<int> BweTest::GetFileSizesBytes(int num_files) {
   // File size chosen from uniform distribution between [100,1000] kB.
   const int kMinKbytes = 100;
   const int kMaxKbytes = 1000;
 
-  Random random(0x12345678);
+  test::Random random(0x12345678);
   std::vector<int> tcp_file_sizes_bytes;
 
   while (num_files-- > 0) {
     tcp_file_sizes_bytes.push_back(random.Rand(kMinKbytes, kMaxKbytes) * 1000);
   }
 
   return tcp_file_sizes_bytes;
 }
 
 std::vector<int64_t> BweTest::GetStartingTimesMs(int num_files) {
   // OFF state behaves as an exp. distribution with mean = 10 seconds.
   const float kMeanMs = 10000.0f;
-  Random random(0x12345678);
+  test::Random random(0x12345678);
 
   std::vector<int64_t> tcp_starting_times_ms;
 
   // Two TCP Flows are initialized simultaneosly at t=0 seconds.
   for (int i = 0; i < 2; ++i, --num_files) {
     tcp_starting_times_ms.push_back(0);
   }
 
   // Other TCP Flows are initialized in an OFF state.
   while (num_files-- > 0) {
     tcp_starting_times_ms.push_back(
         static_cast<int64_t>(random.Exponential(1.0f / kMeanMs)));
   }
 
   return tcp_starting_times_ms;
 }
 
 }  // namespace bwe
 }  // namespace testing
 }  // namespace webrtc