Symbolize JSON output snippets in swarming ASan runs.

This mirrors an earlier change to non-swarming runs:
https://codereview.chromium.org/810643006/

BUG=372458
R=vadimsh@chromium.org

Review URL: https://codereview.chromium.org/865853009

Cr-Commit-Position: refs/heads/master@{#313793}

testing/test_env.py

@@ -105,6 +105,42 @@ def get_asan_env(cmd, lsan):
   return extra_env
 
 
+def get_sanitizer_symbolize_command(json_path=None):
+  """Construct the command to invoke offline symbolization script."""
+  script_path = '../tools/valgrind/asan/asan_symbolize.py'
+  cmd = [sys.executable, script_path]
+  if json_path is not None:
+    cmd.append('--test-summary-json-file=%s' % json_path)
+  return cmd
+
+
+def get_json_path(cmd):
+  """Extract the JSON test summary path from a command line."""
+  json_path_flag = '--test-launcher-summary-output='
+  for arg in cmd:
+    if arg.startswith(json_path_flag):
+      return arg.split(json_path_flag).pop()
+  return None
+
+
+def symbolize_snippets_in_json(cmd, env):
+  """Symbolize output snippets inside the JSON test summary."""
+  json_path = get_json_path(cmd)
+  if json_path is None:
+    return
+
+  try:
+    symbolize_command = get_sanitizer_symbolize_command(json_path=json_path)
+    p = subprocess.Popen(symbolize_command, stderr=subprocess.PIPE, env=env)
+    (_, stderr) = p.communicate()
+  except OSError as e:
+      print 'Exception while symbolizing snippets: %s' % e
+
+  if p.returncode != 0:
+    print "Error: failed to symbolize snippets in JSON:\n"
+    print stderr
+
+
 def run_executable(cmd, env):
   """Runs an executable with:
     - environment variable CR_SOURCE_ROOT set to the root directory.
@@ -123,6 +159,7 @@ def run_executable(cmd, env):
   # Copy logic from  tools/build/scripts/slave/runtest.py.
   asan = '--asan=1' in cmd
   lsan = '--lsan=1' in cmd
+  use_symbolization_script = asan and not lsan
 
   if asan:
     extra_env.update(get_asan_env(cmd, lsan))
@@ -146,16 +183,17 @@ def run_executable(cmd, env):
   env.update(extra_env or {})
   try:
     # See above comment regarding offline symbolization.
-    if asan and not lsan:
+    if use_symbolization_script:
       # Need to pipe to the symbolizer script.
       p1 = subprocess.Popen(cmd, env=env, stdout=subprocess.PIPE,
                             stderr=sys.stdout)
-      p2 = subprocess.Popen([sys.executable,
-                             "../tools/valgrind/asan/asan_symbolize.py"],
+      p2 = subprocess.Popen(get_sanitizer_symbolize_command(),
                             env=env, stdin=p1.stdout)
       p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
       p1.wait()
       p2.wait()
+      # Also feed the out-of-band JSON output to the symbolizer script.
+      symbolize_snippets_in_json(cmd, env)
       return p1.returncode
     else:
       return subprocess.call(cmd, env=env)