Fix an implicit narrowing conversion found by MSVC

webrtc/call/rtp_demuxer_unittest.cc

Index: webrtc/call/rtp_demuxer_unittest.cc
diff --git a/webrtc/call/rtp_demuxer_unittest.cc b/webrtc/call/rtp_demuxer_unittest.cc
index 39dc67b0a17b7ef20f726a6ff699238a280403ac..17c0b0c1268ed738451d5898af68d0e539f37261 100644
--- a/webrtc/call/rtp_demuxer_unittest.cc
+++ b/webrtc/call/rtp_demuxer_unittest.cc
@@ -346,7 +346,8 @@ TEST_F(RtpDemuxerTest, OnRtpPacketCalledOnCorrectSinkByRsid) {
   }
 
   for (size_t i = 0; i < arraysize(rsids); i++) {
-    auto packet = CreatePacketWithSsrcRsid(i, rsids[i]);
+    auto packet = CreatePacketWithSsrcRsid(rtc::dchecked_cast<uint32_t>(i),

[kwiberg-webrtc, 2017/08/22 20:06:05]

There's almost never a reason to use DCHECK instead of CHECK in tests. We don't
care that much about performance, and we never want the checks skipped.

[oprypin_webrtc, 2017/08/22 20:28:39]

Done.

+                                           rsids[i]);
     EXPECT_CALL(sinks[i], OnRtpPacket(SamePacketAs(*packet))).Times(1);
     EXPECT_TRUE(demuxer_.OnRtpPacket(*packet));
   }
@@ -360,7 +361,8 @@ TEST_F(RtpDemuxerTest, OnRtpPacketCalledOnCorrectSinkByMid) {
   }
 
   for (size_t i = 0; i < arraysize(mids); i++) {
-    auto packet = CreatePacketWithSsrcMid(i, mids[i]);
+    auto packet = CreatePacketWithSsrcMid(rtc::dchecked_cast<uint32_t>(i),
+                                          mids[i]);
     EXPECT_CALL(sinks[i], OnRtpPacket(SamePacketAs(*packet))).Times(1);
     EXPECT_TRUE(demuxer_.OnRtpPacket(*packet));
   }
@@ -414,7 +416,7 @@ TEST_F(RtpDemuxerTest, PacketsDeliveredInRightOrder) {
   std::unique_ptr<RtpPacketReceived> packets[5];
   for (size_t i = 0; i < arraysize(packets); i++) {
     packets[i] = CreatePacketWithSsrc(ssrc);
-    packets[i]->SetSequenceNumber(i);
+    packets[i]->SetSequenceNumber(rtc::dchecked_cast<uint16_t>(i));
   }
 
   InSequence sequence;