Don't detect a new frame if a previous packet is used in a previous frame.

webrtc/modules/video_coding/video_packet_buffer_unittest.cc

Index: webrtc/modules/video_coding/video_packet_buffer_unittest.cc
diff --git a/webrtc/modules/video_coding/video_packet_buffer_unittest.cc b/webrtc/modules/video_coding/video_packet_buffer_unittest.cc
index ddb088c63e343ad4caa5dedb70d235c5c971f0df..d938b8b95857efe5e1fcee47ca3f0af40c1f43c5 100644
--- a/webrtc/modules/video_coding/video_packet_buffer_unittest.cc
+++ b/webrtc/modules/video_coding/video_packet_buffer_unittest.cc
@@ -468,5 +468,14 @@ TEST_F(TestPacketBuffer, DontLeakPayloadData) {
   EXPECT_FALSE(Insert(2 + kMaxSize, kKeyFrame, kFirst, kNotLast, 5, data4));
 }
 
+TEST_F(TestPacketBuffer, ContinuousSeqNumDoubleMarkerBit) {
+  Insert(2, kKeyFrame, kNotFirst, kNotLast);
+  Insert(1, kKeyFrame, kFirst, kLast);
+  frames_from_callback_.clear();
+  Insert(3, kKeyFrame, kNotFirst, kLast);
+
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+}
+
 }  // namespace video_coding
 }  // namespace webrtc