[Android] Fix port leak in the forwarder.

tools/android/forwarder2/host_controllers_manager_unittest.cc

+// Copyright 2017 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 "tools/android/forwarder2/host_controllers_manager.h"
+
+#include <cstdio>
+
+#include "base/files/file_util.h"
+#include "base/files/scoped_file.h"
+#include "base/memory/ref_counted.h"
+#include "base/strings/stringprintf.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace forwarder2 {
+
+namespace {
+
+int UnusedGetExitNotifierFD() {
+  return 0;
+}
+
+base::FilePath CreateScript(const std::string script_contents) {
+  base::FilePath script_file;
+  FILE* script_file_handle = base::CreateAndOpenTemporaryFile(&script_file);
+  base::WriteFile(script_file, script_contents.c_str(),
+                  script_contents.length());
+  base::CloseFile(script_file_handle);
+  base::SetPosixFilePermissions(script_file,
+                                base::FILE_PERMISSION_READ_BY_USER |
+                                    base::FILE_PERMISSION_EXECUTE_BY_USER);
+  return script_file;
+}
+
+}  // anonymous namespace
+
+// Ensure that we don't start the adb binary with superfluous file descriptors
+// from the parent process.
+TEST(HostControllersManagerTest, AdbNoExtraFds) {
+  HostControllersManager h(base::Bind(&UnusedGetExitNotifierFD));

[Ted C, 2017/03/28 23:57:37]

I would use something like manager over h (or even hcm to be a bit more
verbose)...same below

[jbudorick, 2017/03/29 01:55:42]

Switched to manager.

+  base::FilePath unrelated_file;
+  base::ScopedFILE open_unrelated_file(
+      CreateAndOpenTemporaryFile(&unrelated_file));
+  const int unrelated_fd = fileno(open_unrelated_file.get());
+  base::FilePath adb_script =
+      CreateScript(base::StringPrintf("#! /bin/sh\n"
+                                      "test ! -e /proc/$$/fd/%d\n",
+                                      unrelated_fd));
+  const std::string serial("0123456789abcdef");
+  const std::string map_call(
+      "forward tcp:12345 localabstract:chrome_device_forwarder");
+  std::string unused_output;
+  ASSERT_TRUE(h.Adb(adb_script.value(), serial, map_call, &unused_output))
+      << "File descriptor " << unrelated_fd << " leaked to child process";
+}
+
+// Ensure that we don't mangle the argument order.
+TEST(HostControllersManagerTest, AdbArgumentSequence) {
+  HostControllersManager h(base::Bind(&UnusedGetExitNotifierFD));
+  base::FilePath adb_script =
+      CreateScript(base::StringPrintf("#! /bin/sh\n"
+                                      "echo -n \"$@\"\n"));
+  const std::string serial("0123456789abcdef");
+  const std::string unmap_call("forward --remove tcp:12345");
+  std::string output;
+  ASSERT_TRUE(h.Adb(adb_script.value(), serial, unmap_call, &output));
+  ASSERT_STREQ("-s 0123456789abcdef forward --remove tcp:12345",
+               output.c_str());
+}
+
+}  // namespace forwarder2