Reland of "Change TWCC send interval to reduce overhead on low BW situations."

webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy_unittest.cc

Index: webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy_unittest.cc
diff --git a/webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy_unittest.cc b/webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy_unittest.cc
index 9821568260c0cf82e0df7c97821409f162271246..dae1f27073f754647bd79ec979a6d46938609bb2 100644
--- a/webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy_unittest.cc
+++ b/webrtc/modules/remote_bitrate_estimator/remote_estimator_proxy_unittest.cc
@@ -42,7 +42,7 @@ class RemoteEstimatorProxyTest : public ::testing::Test {
 
   void Process() {
     clock_.AdvanceTimeMilliseconds(
-        RemoteEstimatorProxy::kDefaultProcessIntervalMs);
+        RemoteEstimatorProxy::kDefaultSendIntervalMs);
     proxy_.Process();
   }
 
@@ -350,4 +350,45 @@ TEST_F(RemoteEstimatorProxyTest, RemovesTimestampsOutOfScope) {
   Process();
 }
 
+TEST_F(RemoteEstimatorProxyTest, TimeUntilNextProcessIsZeroBeforeFirstProcess) {
+  EXPECT_EQ(0, proxy_.TimeUntilNextProcess());
+}
+
+TEST_F(RemoteEstimatorProxyTest, TimeUntilNextProcessIsDefaultOnUnkownBitrate) {
+  Process();
+  EXPECT_EQ(RemoteEstimatorProxy::kDefaultSendIntervalMs,
+            proxy_.TimeUntilNextProcess());
+}
+
+TEST_F(RemoteEstimatorProxyTest, TimeUntilNextProcessIsMinIntervalOn300kbps) {
+  Process();
+  proxy_.OnBitrateChanged(300000);
+  EXPECT_EQ(RemoteEstimatorProxy::kMinSendIntervalMs,
+            proxy_.TimeUntilNextProcess());
+}
+
+TEST_F(RemoteEstimatorProxyTest, TimeUntilNextProcessIsMaxIntervalOn0kbps) {
+  Process();
+  // TimeUntilNextProcess should be limited by |kMaxSendIntervalMs| when
+  // bit rate is small. We choose 0 bps as a special case, which also tests

[stefan-webrtc, 2016/11/07 12:35:45]

s/bit rate/bitrate

[minyue-webrtc, 2016/11/07 12:40:22]

Done.

+  // erroneous behaviors like division-by-zero.
+  proxy_.OnBitrateChanged(0);
+  EXPECT_EQ(RemoteEstimatorProxy::kMaxSendIntervalMs,
+            proxy_.TimeUntilNextProcess());
+}
+
+TEST_F(RemoteEstimatorProxyTest, TimeUntilNextProcessIsMaxIntervalOn20kbps) {
+  Process();
+  proxy_.OnBitrateChanged(20000);
+  EXPECT_EQ(RemoteEstimatorProxy::kMaxSendIntervalMs,
+            proxy_.TimeUntilNextProcess());
+}
+
+TEST_F(RemoteEstimatorProxyTest, TwccReportsUse5PercentOfAvailableBandwidth) {
+  Process();
+  proxy_.OnBitrateChanged(80000);
+  // 80kbps * 0.05 = TwccReportSize(68B * 8b/B) * 1000ms / SendInterval(136ms)
+  EXPECT_EQ(136, proxy_.TimeUntilNextProcess());
+}
+
 }  // namespace webrtc