Add VP8 and H264 depacketizer fuzzers.

webrtc/BUILD.gn

Index: webrtc/BUILD.gn
diff --git a/webrtc/BUILD.gn b/webrtc/BUILD.gn
index f11509cb911f7536ea966691f02e7fefc64d1beb..b26d29f2ee6e2c7dd81873f774dbb097b8653244 100644
--- a/webrtc/BUILD.gn
+++ b/webrtc/BUILD.gn
@@ -281,15 +281,12 @@ source_set("rtc_event_log") {
 }
 
 if (use_libfuzzer || use_drfuzz) {
-  group("webrtc_fuzzers") {
+  # This target is only here for gn to discover fuzzer build targets under
+  # webrtc/test/fuzzers/.
+  group("webrtc_fuzzers_dummy") {
     testonly = true
     deps = [
-      "test/fuzzers:audio_decoder_ilbc_fuzzer",
-      "test/fuzzers:audio_decoder_isac_fuzzer",
-      "test/fuzzers:audio_decoder_isacfix_fuzzer",
-      "test/fuzzers:audio_decoder_opus_fuzzer",
-      "test/fuzzers:vp8_qp_parser_fuzzer",
-      "test/fuzzers:vp9_depacketizer_fuzzer",
+      "test/fuzzers:webrtc_fuzzer_main",
     ]
   }
 }