Update from https://crrev.com/304121

tools/valgrind/chrome_tests.py

 #!/usr/bin/env python
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 ''' Runs various chrome tests through valgrind_test.py.'''
 
 import glob
 import logging
 import multiprocessing
@@ skipping 111 matching lines @@
       self._EnsureBuildDirFound()
       exe_path = os.path.join(self._options.build_dir, exe)
       if not os.path.exists(exe_path):
         raise ExecutableNotFound("Couldn't find '%s'" % exe_path)
 
       # Make sure we don't try to test ASan-built binaries
       # with other dynamic instrumentation-based tools.
       # TODO(timurrrr): also check TSan and MSan?
       # `nm` might not be available, so use try-except.
       try:
-        nm_output = subprocess.check_output(["nm", exe_path])
-        if nm_output.find("__asan_init") != -1:
-          raise BadBinary("You're trying to run an executable instrumented "
-                          "with AddressSanitizer under %s. Please provide "
-                          "an uninstrumented executable." % tool_name)
+        # Do not perform this check on OS X, as 'nm' on 10.6 can't handle
+        # binaries built with Clang 3.5+.
+        if not common.IsMac():
+          nm_output = subprocess.check_output(["nm", exe_path])
+          if nm_output.find("__asan_init") != -1:
+            raise BadBinary("You're trying to run an executable instrumented "
+                            "with AddressSanitizer under %s. Please provide "
+                            "an uninstrumented executable." % tool_name)
       except OSError:
         pass
 
       cmd.append(exe_path)
       # Valgrind runs tests slowly, so slow tests hurt more; show elapased time
       # so we can find the slowpokes.
       cmd.append("--gtest_print_time")
       # Built-in test launcher for gtest-based executables runs tests using
       # multiple process by default. Force the single-process mode back.
       cmd.append("--single-process-tests")
@@ skipping 646 matching lines @@
 
   for t in options.test:
     tests = ChromeTests(options, args, t)
     ret = tests.Run()
     if ret: return ret
   return 0
 
 
 if __name__ == "__main__":
   sys.exit(_main())