Add unit test to check for broker FD leak

sandbox/linux/tests/unit_tests_unittest.cc

 // Copyright 2014 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.
 
 #include <signal.h>
 #include <stdlib.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include "base/logging.h"
 #include "base/posix/eintr_wrapper.h"
 #include "sandbox/linux/tests/unit_tests.h"
 
 namespace sandbox {
 
 namespace {
 
 // Let's not use any of the "magic" values used internally in unit_tests.cc,
 // such as kExpectedValue.
 const int kExpectedExitCode = 100;
 
 SANDBOX_DEATH_TEST(UnitTests,
                    DeathExitCode,
                    DEATH_EXIT_CODE(kExpectedExitCode)) {
   exit(kExpectedExitCode);
 }
 
 const int kExpectedSignalNumber = SIGKILL;
 
 SANDBOX_DEATH_TEST(UnitTests,
                    DeathBySignal,
                    DEATH_BY_SIGNAL(kExpectedSignalNumber)) {
   raise(kExpectedSignalNumber);
 }
 
+SANDBOX_TEST_ALLOW_NOISE(UnitTests, NoisyTest) {
+  LOG(ERROR) << "The cow says moo!";
+}
+
 // Test that a subprocess can be forked() and can use exit(3) instead of
 // _exit(2).
 TEST(UnitTests, SubProcessCanExit) {
   pid_t child = fork();
   ASSERT_NE(-1, child);
 
   if (!child) {
     exit(kExpectedExitCode);
   }
 
   int status = 0;
   pid_t waitpid_ret = HANDLE_EINTR(waitpid(child, &status, 0));
   EXPECT_EQ(child, waitpid_ret);
   EXPECT_TRUE(WIFEXITED(status));
   EXPECT_EQ(kExpectedExitCode, WEXITSTATUS(status));
 }
 
 }  // namespace
 
 }  // namespace sandbox