Allow parsing empty RTCP TargetBitrate messages, but stop sending them.

webrtc/video/payload_router_unittest.cc

Index: webrtc/video/payload_router_unittest.cc
diff --git a/webrtc/video/payload_router_unittest.cc b/webrtc/video/payload_router_unittest.cc
index e316695338a1c7a7e31a8a46afa727dc3b0f88eb..eba26695534a4eb7cb642798477f591071b449aa 100644
--- a/webrtc/video/payload_router_unittest.cc
+++ b/webrtc/video/payload_router_unittest.cc
@@ -178,6 +178,29 @@ TEST(PayloadRouterTest, SimulcastTargetBitrate) {
   payload_router.OnBitrateAllocationUpdated(bitrate);
 }
 
+TEST(PayloadRouterTest, SimulcastTargetBitrateWithInactiveStream) {
+  NiceMock<MockRtpRtcp> rtp_1;
+  NiceMock<MockRtpRtcp> rtp_2;
+  std::vector<RtpRtcp*> modules;
+  modules.push_back(&rtp_1);
+  modules.push_back(&rtp_2);
+  PayloadRouter payload_router(modules, 42);
+  payload_router.SetActive(true);
+
+  BitrateAllocation bitrate;
+  bitrate.SetBitrate(0, 0, 10000);
+  bitrate.SetBitrate(0, 1, 20000);
+
+  BitrateAllocation layer0_bitrate;

[danilchap, 2017/06/20 10:29:27]

is it same as bitrate? why do you need two variables?

[sprang_webrtc, 2017/06/20 15:24:34]

I don't, I was just lazy (copy/paste from other test).
Fixed.

+  layer0_bitrate.SetBitrate(0, 0, 10000);
+  layer0_bitrate.SetBitrate(0, 1, 20000);
+
+  EXPECT_CALL(rtp_1, SetVideoBitrateAllocation(layer0_bitrate)).Times(1);
+  EXPECT_CALL(rtp_2, SetVideoBitrateAllocation(_)).Times(0);

[danilchap, 2017/06/20 10:29:26]

can you explain (with test name or comments, better both) why expectation are
like this?

[sprang_webrtc, 2017/06/20 15:24:34]

Done.

+
+  payload_router.OnBitrateAllocationUpdated(bitrate);
+}
+
 TEST(PayloadRouterTest, SvcTargetBitrate) {
   NiceMock<MockRtpRtcp> rtp_1;
   std::vector<RtpRtcp*> modules;