Mark VideoSendTiming flags as invalid by default.

Bug: none
Change-Id: I962df8a55c022193cb3ec036c3cf35f34f9b2412
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/222611
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Sam Zackrisson <saza@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34322}
diff --git a/api/video/video_timing.h b/api/video/video_timing.h
index fbd9225..80320da 100644
--- a/api/video/video_timing.h
+++ b/api/video/video_timing.h
@@ -41,7 +41,7 @@
   uint16_t pacer_exit_delta_ms;
   uint16_t network_timestamp_delta_ms;
   uint16_t network2_timestamp_delta_ms;
-  uint8_t flags;
+  uint8_t flags = TimingFrameFlags::kInvalid;
 };
 
 // Used to report precise timings of a 'timing frames'. Contains all important
diff --git a/test/fuzzers/rtp_packet_fuzzer.cc b/test/fuzzers/rtp_packet_fuzzer.cc
index 5f649fe..3f2fc5e 100644
--- a/test/fuzzers/rtp_packet_fuzzer.cc
+++ b/test/fuzzers/rtp_packet_fuzzer.cc
@@ -115,10 +115,11 @@
         VideoContentType content_type;
         packet.GetExtension<VideoContentTypeExtension>(&content_type);
         break;
-      case kRtpExtensionVideoTiming:
+      case kRtpExtensionVideoTiming: {
         VideoSendTiming timing;
         packet.GetExtension<VideoTimingExtension>(&timing);
         break;
+      }
       case kRtpExtensionRtpStreamId: {
         std::string rsid;
         packet.GetExtension<RtpStreamId>(&rsid);