Check empty NALUs in H.265 depacketizer.

This is cherry-picked from WebKit's patch for fixing a fuzzer failure.
The original patch: https://github.com/WebKit/WebKit/pull/30438

Bug: chromium:41480904
Change-Id: Ic8eddb9de816c4c8d720dac6d4c55d1db3f0596e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/356361
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Jianlin Qiu <jianlin.qiu@intel.com>
Cr-Commit-Position: refs/heads/main@{#42598}
diff --git a/modules/rtp_rtcp/source/rtp_packetizer_h265.cc b/modules/rtp_rtcp/source/rtp_packetizer_h265.cc
index 5f10120..775c50c 100644
--- a/modules/rtp_rtcp/source/rtp_packetizer_h265.cc
+++ b/modules/rtp_rtcp/source/rtp_packetizer_h265.cc
@@ -26,6 +26,10 @@
     : limits_(limits), num_packets_left_(0) {
   for (const auto& nalu :
        H264::FindNaluIndices(payload.data(), payload.size())) {
+    if (!nalu.payload_size) {
+      input_fragments_.clear();
+      return;
+    }
     input_fragments_.push_back(
         payload.subview(nalu.payload_start_offset, nalu.payload_size));
   }