Add a mojo::test::ScopedTestDir and convert tests to use it.

mojo/edk/system/multiprocess_message_pipe_unittest.cc

 // Copyright 2013 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 <stdint.h>
 #include <stdio.h>
 #include <string.h>
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
-#include "base/files/file_path.h"
-#include "base/files/file_util.h"
-#include "base/files/scoped_temp_dir.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "build/build_config.h"  // TODO(vtl): Remove this.
 #include "mojo/edk/embedder/platform_shared_buffer.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/system/channel.h"
 #include "mojo/edk/system/dispatcher.h"
 #include "mojo/edk/system/message_pipe.h"
 #include "mojo/edk/system/message_pipe_test_utils.h"
 #include "mojo/edk/system/platform_handle_dispatcher.h"
 #include "mojo/edk/system/raw_channel.h"
 #include "mojo/edk/system/shared_buffer_dispatcher.h"
 #include "mojo/edk/system/test_utils.h"
+#include "mojo/edk/test/scoped_test_dir.h"
 #include "mojo/edk/test/test_utils.h"
 #include "mojo/edk/util/scoped_file.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace system {
 namespace {
 
 class MultiprocessMessagePipeTest
     : public test::MultiprocessMessagePipeTestBase {};
@@ skipping 402 matching lines @@
   }
 
   return 0;
 }
 
 class MultiprocessMessagePipeTestWithPipeCount
     : public test::MultiprocessMessagePipeTestBase,
       public testing::WithParamInterface<size_t> {};
 
 TEST_P(MultiprocessMessagePipeTestWithPipeCount, PlatformHandlePassing) {
-  base::ScopedTempDir temp_dir;
-  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  mojo::test::ScopedTestDir test_dir;
 
   helper()->StartChild("CheckPlatformHandleFile");
 
   scoped_refptr<ChannelEndpoint> ep;
   scoped_refptr<MessagePipe> mp(MessagePipe::CreateLocalProxy(&ep));
   Init(ep);
 
   std::vector<scoped_refptr<PlatformHandleDispatcher>> dispatchers;
   std::vector<DispatcherTransport> transports;
 
   size_t pipe_count = GetParam();
   for (size_t i = 0; i < pipe_count; ++i) {
-    base::FilePath unused;
-    util::ScopedFILE fp(
-        CreateAndOpenTemporaryFileInDir(temp_dir.path(), &unused));
+    util::ScopedFILE fp(test_dir.CreateFile());
     const std::string world("world");
     CHECK_EQ(fwrite(&world[0], 1, world.size(), fp.get()), world.size());
     fflush(fp.get());
     rewind(fp.get());
 
     scoped_refptr<PlatformHandleDispatcher> dispatcher =
         PlatformHandleDispatcher::Create(embedder::ScopedPlatformHandle(
             mojo::test::PlatformHandleFromFILE(fp.Pass())));
     dispatchers.push_back(dispatcher);
     DispatcherTransport transport(
@@ skipping 32 matching lines @@
 // Android multi-process tests are not executing the new process. This is flaky.
 #if defined(OS_POSIX) && !defined(OS_ANDROID)
 INSTANTIATE_TEST_CASE_P(PipeCount,
                         MultiprocessMessagePipeTestWithPipeCount,
                         testing::Values(1u, 128u, 140u));
 #endif
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo