[coverage] Enable sanitizer coverage.

tools/testrunner/local/commands.py

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 89 matching lines @@
     except OSError:
       sys.stderr.write('Error: Process %s already ended.\n' % process.pid)
 
   # Pseudo object to communicate with timer thread.
   timeout_result = [False]
 
   timer = Timer(timeout, kill_process, [process, timeout_result])
   timer.start()
   stdout, stderr = process.communicate()
   timer.cancel()
-  return process.returncode, timeout_result[0], stdout, stderr
+
+  return output.Output(
+      process.returncode,
+      timeout_result[0],
+      stdout,
+      stderr,
+      process.pid,
+  )
 
 
 def Execute(args, verbose=False, timeout=None):
   args = [ c for c in args if c != "" ]
-  exit_code, timed_out, stdout, stderr = RunProcess(
-    verbose,
-    timeout,
-    args=args,
-  )
-  return output.Output(exit_code, timed_out, stdout, stderr)
+  return RunProcess(verbose, timeout, args=args)