Fix sync unit test.

sync/syncable/syncable_unittest.cc

 // Copyright (c) 2012 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 <string>
 
 #include "base/compiler_specific.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/location.h"
@@ skipping 1406 matching lines @@
     : Directory(encryptor, handler, NULL, backing_store),
       backing_store_(backing_store) {
 }
 
 TestDirectory::~TestDirectory() { }
 
 TEST(OnDiskSyncableDirectory, FailInitialWrite) {
   FakeEncryptor encryptor;
   TestUnrecoverableErrorHandler handler;
   ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
   FilePath file_path = temp_dir.path().Append(
       FILE_PATH_LITERAL("Test.sqlite3"));
   std::string name = "user@x.com";
   NullDirectoryChangeDelegate delegate;
 
   scoped_ptr<TestDirectory> test_dir(
       TestDirectory::Create(&encryptor, &handler, name, file_path));
 
   test_dir->StartFailingSaveChanges();
   ASSERT_EQ(FAILED_INITIAL_WRITE, test_dir->Open(name, &delegate,
@@ skipping 602 matching lines @@
   EXPECT_TRUE(CreateWithDefaultTag(factory_.NewServerId(), true));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewServerId(), true));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewServerId(), false));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewLocalId(), false));
   EXPECT_FALSE(CreateWithDefaultTag(factory_.NewLocalId(), true));
 }
 
 }  // namespace
 }  // namespace syncable
 }  // namespace syncer