Make WEBRTC_UNSAFE_FUZZER_MODE dependent only on use_fuzzing_engine

The level of optimization is irrelevant -- only whether the build is
targeting a fuzzer or not.

Bug: chromium:1483560, chromium:847106, chromium:844647, chromium:646404
Change-Id: I8784883ed222b08b4d4313782175a9550e3e3ea5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/320800
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Christoffer Jansson <jansson@google.com>
Auto-Submit: Greg Thompson <grt@chromium.org>
Reviewed-by: Jonathan Metzman <metzman@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Christoffer Jansson <jansson@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40778}
diff --git a/BUILD.gn b/BUILD.gn
index c247afb..cc86183 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -467,7 +467,7 @@
     ]
   }
 
-  if (use_fuzzing_engine && optimize_for_fuzzing) {
+  if (use_fuzzing_engine) {
     # Used in Chromium's overrides to disable logging
     defines += [ "WEBRTC_UNSAFE_FUZZER_MODE" ]
   }