Move thread from test/ to util/thread/.

test/thread.cc

-// Copyright 2015 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 "test/thread.h"
-
-#include "gtest/gtest.h"
-
-namespace crashpad {
-namespace test {
-
-Thread::Thread() : platform_thread_(0) {
-}
-
-Thread::~Thread() {
-  EXPECT_FALSE(platform_thread_);
-}
-
-}  // namespace test
-}  // namespace crashpad