Make sure temporal layered screenshare frames are sent in at least 2s.

webrtc/modules/video_coding/codecs/vp8/screenshare_layers_unittest.cc

Index: webrtc/modules/video_coding/codecs/vp8/screenshare_layers_unittest.cc
diff --git a/webrtc/modules/video_coding/codecs/vp8/screenshare_layers_unittest.cc b/webrtc/modules/video_coding/codecs/vp8/screenshare_layers_unittest.cc
index 7be4eb1bb228928609d0a9a41aec5754ba0e71b2..4a6f6c6d79017c7edfd62aadc10ef5075c70642e 100644
--- a/webrtc/modules/video_coding/codecs/vp8/screenshare_layers_unittest.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/screenshare_layers_unittest.cc
@@ -359,8 +359,7 @@ TEST_F(ScreenshareLayerTest, TooHighBitrate) {
     }
   }
 
-  EXPECT_EQ(5, tl0_frames);
-  EXPECT_EQ(45, tl1_frames);
+  EXPECT_EQ(50, tl0_frames + tl1_frames);
   EXPECT_EQ(50, dropped_frames);
 }
 
@@ -441,6 +440,32 @@ TEST_F(ScreenshareLayerTest, EncoderDrop) {
   layers_->FrameEncoded(frame_size_, timestamp, kDefaultQp);
 }
 
+TEST_F(ScreenshareLayerTest, RespectsMaxIntervalBetweenFrames) {
+  const int kLowBitrateKbps = 50;
+  const int kLargeFrameSizeBytes = 100000;
+  const uint32_t kStartTimestamp = 1234;
+
+  vpx_codec_enc_cfg_t cfg;
+  layers_->ConfigureBitrates(kLowBitrateKbps, kLowBitrateKbps, 5, &cfg);
+
+  EXPECT_EQ(ScreenshareLayers::kTl0Flags,
+            layers_->EncodeFlags(kStartTimestamp));
+  layers_->FrameEncoded(kLargeFrameSizeBytes, kStartTimestamp, kDefaultQp);
+
+  const uint32_t kTwoSecondsLater =
+      kStartTimestamp + (ScreenshareLayers::kMaxFrameIntervalMs * 90);
+
+  // Sanity check, repayment time should exceed kMaxFrameIntervalMs.
+  ASSERT_GT(kStartTimestamp + 90 * (kLargeFrameSizeBytes * 8) / kLowBitrateKbps,
+            kStartTimestamp + (ScreenshareLayers::kMaxFrameIntervalMs * 90));
+
+  EXPECT_EQ(-1, layers_->EncodeFlags(kTwoSecondsLater));
+  // More than two seconds has passed since last frame, one should be emitted
+  // even if bitrate target is then exceeded.
+  EXPECT_EQ(ScreenshareLayers::kTl0Flags,
+            layers_->EncodeFlags(kTwoSecondsLater + 90));
+}
+
 TEST_F(ScreenshareLayerTest, UpdatesHistograms) {
   ConfigureBitrates();
   vpx_codec_enc_cfg_t cfg;