Update screen simulcast config and fix periodic encoder param update

webrtc/video/vie_encoder_unittest.cc

Index: webrtc/video/vie_encoder_unittest.cc
diff --git a/webrtc/video/vie_encoder_unittest.cc b/webrtc/video/vie_encoder_unittest.cc
index 8c57d885be3193234935d85707a2813c4ddd8e7b..ec129cac3a69f87febedf7176c6d707029f3f38a 100644
--- a/webrtc/video/vie_encoder_unittest.cc
+++ b/webrtc/video/vie_encoder_unittest.cc
@@ -1659,4 +1659,52 @@ TEST_F(ViEEncoderTest, DoesntAdaptDownPastMinFramerate) {
   }
   vie_encoder_->Stop();
 }
+
+TEST_F(ViEEncoderTest, PriodicallyUpdatesChannelParameters) {
+  const int kFrameWidth = 1280;
+  const int kFrameHeight = 720;
+  const int kLowFps = 2;
+  const int kHighFps = 30;
+
+  rtc::ScopedFakeClock fake_clock;
+  vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
+
+  int64_t timestamp_ms = 1000;
+
+  // Insert 2 seconds of 2fps video.
+  for (int i = 0; i < kLowFps * 2; ++i) {
+    video_source_.IncomingCapturedFrame(
+        CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
+    sink_.WaitForEncodedFrame(timestamp_ms);
+    timestamp_ms += 1000 / kLowFps;
+    fake_clock.AdvanceTimeMicros((1000 / kLowFps) * 1000);
+  }
+
+  // Make sure encoder is updated with new target.
+  vie_encoder_->OnBitrateUpdated(kTargetBitrateBps, 0, 0);
+  video_source_.IncomingCapturedFrame(
+      CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
+  sink_.WaitForEncodedFrame(timestamp_ms);
+  timestamp_ms += 1000 / kLowFps;
+  fake_clock.AdvanceTimeMicros((1000 / kLowFps) * 1000);
+
+  EXPECT_EQ(kLowFps, fake_encoder_.GetConfiguredInputFramerate());
+
+  // Insert 30fps frames for just a little more than the forced update period.
+  const int kVcmTimerIntervalFrames =
+      (vcm::VCMProcessTimer::kDefaultProcessIntervalMs * kHighFps) / 1000;
+  for (int i = 0; i < kVcmTimerIntervalFrames + 2; ++i) {
+    video_source_.IncomingCapturedFrame(
+        CreateFrame(timestamp_ms, kFrameWidth, kFrameHeight));
+    sink_.WaitForEncodedFrame(timestamp_ms);
+    timestamp_ms += 1000 / kHighFps;
+    fake_clock.AdvanceTimeMicros((1000 / kHighFps) * 1000);
+  }
+
+  // Don expect correct measurement just yet, but it should be higher than
+  // before.
+  EXPECT_GT(fake_encoder_.GetConfiguredInputFramerate(), kLowFps);
+
+  vie_encoder_->Stop();
+}
 }  // namespace webrtc