Structure of BBR's implementation,some main classes and functions which are going to be used

webrtc/modules/remote_bitrate_estimator/test/bwe.cc

Index: webrtc/modules/remote_bitrate_estimator/test/bwe.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/test/bwe.cc b/webrtc/modules/remote_bitrate_estimator/test/bwe.cc
index 086e3c3264228e2089c4d0ee6795cc01d00c22ef..bc5c3f32e1462a16253f7357cbccfb010ff29109 100644
--- a/webrtc/modules/remote_bitrate_estimator/test/bwe.cc
+++ b/webrtc/modules/remote_bitrate_estimator/test/bwe.cc
@@ -13,6 +13,7 @@
 #include <limits>
 
 #include "webrtc/base/constructormagic.h"
+#include "webrtc/modules/remote_bitrate_estimator/test/estimators/bbr.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/estimators/nada.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/estimators/remb.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/estimators/send_side.h"
@@ -93,6 +94,8 @@ BweSender* CreateBweSender(BandwidthEstimatorType estimator,
       return new SendSideBweSender(kbps, observer, clock);
     case kNadaEstimator:
       return new NadaBweSender(kbps, observer, clock);
+    case kBbrEstimator:
+      return new BbrBweSender();
     case kTcpEstimator:
       FALLTHROUGH();
     case kNullEstimator:
@@ -112,6 +115,8 @@ BweReceiver* CreateBweReceiver(BandwidthEstimatorType type,
       return new SendSideBweReceiver(flow_id);
     case kNadaEstimator:
       return new NadaBweReceiver(flow_id);
+    case kBbrEstimator:
+      return new BbrBweReceiver(flow_id);
     case kTcpEstimator:
       return new TcpBweReceiver(flow_id);
     case kNullEstimator: