Add the MultiprocessExec test and its test

util/test/executable_path_mac.cc

+// Copyright 2014 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "util/test/executable_path.h"
+
+#include <mach-o/dyld.h>
+#include <stdint.h>
+
+#include "base/logging.h"
+
+namespace crashpad {
+namespace test {
+
+base::FilePath ExecutablePath() {
+  uint32_t executable_length = 0;
+  _NSGetExecutablePath(NULL, &executable_length);
+  DCHECK_GT(executable_length, 1u);
+  std::string executable_path(executable_length, std::string::value_type());
+  int rv = _NSGetExecutablePath(&executable_path[0], &executable_length);
+  DCHECK_EQ(rv, 0);
+
+  return base::FilePath(executable_path);
+}
+
+}  // namespace test
+}  // namespace crashpad