Remove GetFeedbackInterval in sender side BWE.

webrtc/modules/congestion_controller/probe_bitrate_estimator_unittest.cc

Index: webrtc/modules/congestion_controller/probe_bitrate_estimator_unittest.cc
diff --git a/webrtc/modules/congestion_controller/probe_bitrate_estimator_unittest.cc b/webrtc/modules/congestion_controller/probe_bitrate_estimator_unittest.cc
index f86c93fae3aeee6fd26475a3123fad3dadcdffbe..5686f57724ca79f63e9ecb0943d4503a51f21aec 100644
--- a/webrtc/modules/congestion_controller/probe_bitrate_estimator_unittest.cc
+++ b/webrtc/modules/congestion_controller/probe_bitrate_estimator_unittest.cc
@@ -193,4 +193,21 @@ TEST_F(TestProbeBitrateEstimator, IgnoreSizeFirstReceivePacket) {
   EXPECT_NEAR(measured_bps_, 800000, 10);
 }
 
+TEST_F(TestProbeBitrateEstimator, NoLastEstimatedBitrateBps) {
+  EXPECT_FALSE(probe_bitrate_estimator_.FetchAndResetLastEstimatedBitrateBps());
+}
+
+TEST_F(TestProbeBitrateEstimator, FetchLastEstimatedBitrateBps) {
+  AddPacketFeedback(0, 1000, 0, 10);
+  AddPacketFeedback(0, 1000, 10, 20);
+  AddPacketFeedback(0, 1000, 20, 30);
+  AddPacketFeedback(0, 1000, 30, 40);
+
+  auto estimated_bitrate_bps =
+      probe_bitrate_estimator_.FetchAndResetLastEstimatedBitrateBps();
+  EXPECT_TRUE(estimated_bitrate_bps);
+  EXPECT_NEAR(*estimated_bitrate_bps, 800000, 10);
+  EXPECT_FALSE(probe_bitrate_estimator_.FetchAndResetLastEstimatedBitrateBps());
+}
+
 }  // namespace webrtc