Add the MultiprocessExec test and its test

util/test/multiprocess_exec_test.cc

Index: util/test/multiprocess_exec_test.cc
diff --git a/util/test/multiprocess_exec_test.cc b/util/test/multiprocess_exec_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0edbbcf0feb7117739205029d0fe953f17e2bf0a
--- /dev/null
+++ b/util/test/multiprocess_exec_test.cc
@@ -0,0 +1,61 @@
+// 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/multiprocess_exec.h"
+
+#include <unistd.h>
+
+#include "base/basictypes.h"
+#include "gtest/gtest.h"
+#include "util/file/fd_io.h"
+#include "util/test/errors.h"
+#include "util/test/executable_path.h"
+
+namespace {
+
+using namespace crashpad;
+using namespace crashpad::test;
+
+class TestMultiprocessExec final : public MultiprocessExec {
+ public:
+  TestMultiprocessExec() : MultiprocessExec() {}
+
+  ~TestMultiprocessExec() {}
+
+ private:
+  virtual void MultiprocessParent() override {
+    int write_fd = WritePipeFD();
+    char c = 'z';
+    ssize_t rv = WriteFD(write_fd, &c, 1);
+    ASSERT_EQ(1, rv) << ErrnoMessage("write");
+
+    int read_fd = ReadPipeFD();
+    rv = ReadFD(read_fd, &c, 1);
+    ASSERT_EQ(1, rv) << ErrnoMessage("read");
+    EXPECT_EQ('Z', c);
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(TestMultiprocessExec);
+};
+
+TEST(MultiprocessExec, MultiprocessExec) {
+  TestMultiprocessExec multiprocess_exec;
+  base::FilePath test_executable = ExecutablePath();
+  std::string child_test_executable =
+      test_executable.value() + "_multiprocess_exec_test_child";
+  multiprocess_exec.SetChildCommand(child_test_executable, NULL);
+  multiprocess_exec.Run();
+}
+
+}  // namespace