[libFuzzer][chrome] Dont set an rss_limit_mb. (#4135)

Chrome fuzzing thinks it's not needed because the OOM killer can be
relied on.
We didn't have one for AFL.

Related: #4134

src/clusterfuzz/_internal/bot/fuzzers/libFuzzer/fuzzer.py

@@ -14,6 +14,7 @@
 """libFuzzer fuzzer."""
 import psutil
 
+from clusterfuzz._internal.base import utils
 from clusterfuzz._internal.bot.fuzzers import builtin
 from clusterfuzz._internal.bot.fuzzers import options
 from clusterfuzz._internal.bot.fuzzers.libFuzzer import constants
@@ -44,7 +45,10 @@ def get_arguments(fuzzer_path) -> options.FuzzerArguments:
   if timeout is None or timeout > constants.DEFAULT_TIMEOUT_LIMIT:
     arguments[constants.TIMEOUT_FLAGNAME] = constants.DEFAULT_TIMEOUT_LIMIT
 
-  if not rss_limit_mb:
+  if not rss_limit_mb and utils.is_chromium():
+    # TODO(metzman/alhijazi): Monitor if we are crashing the bots.
+    arguments[constants.RSS_LIMIT_FLAGNAME] = 0
+  elif not rss_limit_mb:
     arguments[constants.RSS_LIMIT_FLAGNAME] = constants.DEFAULT_RSS_LIMIT_MB
   else:
     # psutil gives the total amount of memory in bytes, but we're only dealing