Add totalDecodeTime to RTCInboundRTPStreamStats

Pull request to WebRTC stats specification:
https://github.com/w3c/webrtc-stats/pull/450

Bug: webrtc:10775
Change-Id: Id032cb324724329fee284ebc84595b9c39208ab8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/144035
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28440}
diff --git a/pc/rtc_stats_integrationtest.cc b/pc/rtc_stats_integrationtest.cc
index 79d6faf..a05fa0e 100644
--- a/pc/rtc_stats_integrationtest.cc
+++ b/pc/rtc_stats_integrationtest.cc
@@ -805,12 +805,15 @@
         *inbound_stream.media_type == "video") {
       verifier.TestMemberIsDefined(inbound_stream.frames_decoded);
       verifier.TestMemberIsDefined(inbound_stream.key_frames_decoded);
+      verifier.TestMemberIsNonNegative<double>(
+          inbound_stream.total_decode_time);
       // The integration test is not set up to test screen share; don't require
       // this to be present.
       verifier.MarkMemberTested(inbound_stream.content_type, true);
     } else {
       verifier.TestMemberIsUndefined(inbound_stream.frames_decoded);
       verifier.TestMemberIsUndefined(inbound_stream.key_frames_decoded);
+      verifier.TestMemberIsUndefined(inbound_stream.total_decode_time);
       verifier.TestMemberIsUndefined(inbound_stream.content_type);
     }
     return verifier.ExpectAllMembersSuccessfullyTested();