Fix report symbolization on swarming bots.

testing/test_env.py

Index: testing/test_env.py
diff --git a/testing/test_env.py b/testing/test_env.py
index 4c194277bf33090c31097025cf7c85064413a10a..5980ae9229903ae4c7fc9b0aa875f3111c8920fc 100755
--- a/testing/test_env.py
+++ b/testing/test_env.py
@@ -173,7 +173,8 @@ def run_executable(cmd, env):
       # Need to pipe to the symbolizer script.
       p1 = subprocess.Popen(cmd, env=env, stdout=subprocess.PIPE,
                             stderr=sys.stdout)
-      p2 = subprocess.Popen(["../tools/valgrind/asan/asan_symbolize.py"],
+      p2 = subprocess.Popen(["../tools/valgrind/asan/asan_symbolize.py",
+                             "--executable_path=%s" % cmd[0]],
                             env=env, stdin=p1.stdout)
       p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
       p1.wait()