Add test for dropping repeated NTP timestamps.

webrtc/video/video_capture_input_unittest.cc

Index: webrtc/video/video_capture_input_unittest.cc
diff --git a/webrtc/video/video_capture_input_unittest.cc b/webrtc/video/video_capture_input_unittest.cc
index cc4b5b08d227e4b5b54b480713d04097b3b7af2e..2ab7e51dc4599f9a5daadd4e7644f290f3f59ec3 100644
--- a/webrtc/video/video_capture_input_unittest.cc
+++ b/webrtc/video/video_capture_input_unittest.cc
@@ -139,7 +139,7 @@ TEST_F(VideoCaptureInputTest, DoesNotRetainHandleNorCopyBuffer) {
 }
 
 TEST_F(VideoCaptureInputTest, TestNtpTimeStampSetIfRenderTimeSet) {
-  input_frames_.push_back(CreateVideoFrame(static_cast<uint8_t>(0)));
+  input_frames_.push_back(CreateVideoFrame(0));
   input_frames_[0]->set_render_time_ms(5);
   input_frames_[0]->set_ntp_time_ms(0);
 
@@ -150,7 +150,7 @@ TEST_F(VideoCaptureInputTest, TestNtpTimeStampSetIfRenderTimeSet) {
 }
 
 TEST_F(VideoCaptureInputTest, TestRtpTimeStampSet) {
-  input_frames_.push_back(CreateVideoFrame(static_cast<uint8_t>(0)));
+  input_frames_.push_back(CreateVideoFrame(0));
   input_frames_[0]->set_render_time_ms(0);
   input_frames_[0]->set_ntp_time_ms(1);
   input_frames_[0]->set_timestamp(0);
@@ -161,6 +161,32 @@ TEST_F(VideoCaptureInputTest, TestRtpTimeStampSet) {
             input_frames_[0]->ntp_time_ms() * 90);
 }
 
+TEST_F(VideoCaptureInputTest, DropsFramesWithSameOrOldNtpTimestamp) {
+  input_frames_.push_back(CreateVideoFrame(0));
+
+  input_frames_[0]->set_ntp_time_ms(17);
+  AddInputFrame(input_frames_[0]);
+  WaitOutputFrame();
+  EXPECT_EQ(output_frames_[0]->timestamp(),
+            input_frames_[0]->ntp_time_ms() * 90);
+
+  // Repeat frame with the same NTP timestamp should drop.
+  AddInputFrame(input_frames_[0]);
+  EXPECT_EQ(kEventTimeout, output_frame_event_->Wait(FRAME_TIMEOUT_MS));
+
+  // As should frames with a decreased NTP timestamp.
+  input_frames_[0]->set_ntp_time_ms(input_frames_[0]->ntp_time_ms() - 1);
+  AddInputFrame(input_frames_[0]);
+  EXPECT_EQ(kEventTimeout, output_frame_event_->Wait(FRAME_TIMEOUT_MS));
+
+  // But delivering with an increased NTP timestamp should succeed.
+  input_frames_[0]->set_ntp_time_ms(4711);
+  AddInputFrame(input_frames_[0]);
+  WaitOutputFrame();
+  EXPECT_EQ(output_frames_[1]->timestamp(),
+            input_frames_[0]->ntp_time_ms() * 90);
+}
+
 TEST_F(VideoCaptureInputTest, TestTextureFrames) {
   const int kNumFrame = 3;
   for (int i = 0 ; i < kNumFrame; ++i) {