Rewrote the PRNG using an xorshift* algorithm and moved the files from test/ to base/.

webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc

Index: webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc b/webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc
index 120f50166ffde4d547db824c31476a86f1add7ae..c3a65c1832aedc759e7215c7474908eaf20f1a22 100644
--- a/webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc
+++ b/webrtc/modules/remote_bitrate_estimator/test/bwe_test_framework.cc
@@ -391,7 +391,7 @@ void JitterFilter::SetMaxJitter(int64_t max_jitter_ms) {
 }
 
 namespace {
-inline int64_t TruncatedNSigmaGaussian(test::Random* const random,
+inline int64_t TruncatedNSigmaGaussian(Random* const random,
                                        int64_t mean,
                                        int64_t std_dev) {
   int64_t gaussian_random = random->Gaussian(mean, std_dev);