Frame continuity is now tested as soon as a frame is inserted into the FrameBuffer.

webrtc/modules/video_coding/frame_buffer2_unittest.cc

Index: webrtc/modules/video_coding/frame_buffer2_unittest.cc
diff --git a/webrtc/modules/video_coding/frame_buffer2_unittest.cc b/webrtc/modules/video_coding/frame_buffer2_unittest.cc
index ad776df310b85c8404512fbb2a0250f71efa6a78..17c2274db4a5e09097b1296bd44eb5a0d595d9db 100644
--- a/webrtc/modules/video_coding/frame_buffer2_unittest.cc
+++ b/webrtc/modules/video_coding/frame_buffer2_unittest.cc
@@ -129,7 +129,7 @@ class TestFrameBuffer2 : public ::testing::Test {
     for (size_t r = 0; r < references.size(); ++r)
       frame->references[r] = references[r];
 
-    buffer_.InsertFrame(std::move(frame));
+    last_continuous_frames_.push_back(buffer_.InsertFrame(std::move(frame)));
   }
 
   void ExtractFrame(int64_t max_wait_time = 0) {
@@ -157,6 +157,12 @@ class TestFrameBuffer2 : public ::testing::Test {
     ASSERT_EQ(spatial_layer, frames_[index]->spatial_layer);
   }
 
+  void CheckLastContinuousFrame(size_t index, int picture_id) {
+    rtc::CritScope lock(&crit_);
+    ASSERT_LT(index, last_continuous_frames_.size());
+    ASSERT_EQ(picture_id, last_continuous_frames_[index]);
+  }
+
   void CheckNoFrame(size_t index) {
     rtc::CritScope lock(&crit_);
     ASSERT_LT(index, frames_.size());
@@ -189,6 +195,7 @@ class TestFrameBuffer2 : public ::testing::Test {
   ::testing::NiceMock<VCMJitterEstimatorMock> jitter_estimator_;
   FrameBuffer buffer_;
   std::vector<std::unique_ptr<FrameObject>> frames_;
+  std::vector<int> last_continuous_frames_;
   Random rand_;
 
   int64_t max_wait_time_;
@@ -358,5 +365,22 @@ TEST_F(TestFrameBuffer2, ProtectionMode) {
   ExtractFrame();
 }
 
+TEST_F(TestFrameBuffer2, LastContinuousFrameSingleStream) {

[danilchap, 2016/09/12 12:20:14]

It helps when test name describes both scenario and expected result.
If you have several scenarios (look like you do) - make several smaller tests.

+  uint16_t pid = Rand();
+  uint32_t ts = Rand();
+
+  InsertFrame(pid, 0, ts, false);
+  InsertFrame(pid + 2, 0, ts, false, pid + 1);
+  InsertFrame(pid + 1, 0, ts, false, pid);
+  InsertFrame(pid + 4, 0, ts, false, pid + 3);
+  InsertFrame(pid + 5, 0, ts, false);
+
+  CheckLastContinuousFrame(0, pid);

[danilchap, 2016/09/12 12:20:14]

May be make InsertFrame return the result of buffer_.InsertFrame and merge
InsertFrame & CheckLastContinuousFrame calls. Less fixture state should make
more clear what this 5 calls refer to:
EXPECT_EQ(static_cast<int>(pid), InsertFrame(pid, 0, ts, false));
EXPECT_EQ(static_cast<int>(pid), InsertFrame(pid + 2, 0, ts, false, pid + 1);
...

[philipel, 2016/09/16 14:01:20]

Done.

+  CheckLastContinuousFrame(1, pid);
+  CheckLastContinuousFrame(2, pid + 2);
+  CheckLastContinuousFrame(3, pid + 2);
+  CheckLastContinuousFrame(4, pid + 5);
+}

[danilchap, 2016/09/12 12:20:14]

May be add a test case where InsertFrame return -1

[philipel, 2016/09/16 14:01:20]

Done.

+
 }  // namespace video_coding
 }  // namespace webrtc