Use TaskScheduler instead of WorkerPool in file_ios.cc.

net/disk_cache/disk_cache_test_base.h

 // 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.
 
 #ifndef NET_DISK_CACHE_DISK_CACHE_TEST_BASE_H_
 #define NET_DISK_CACHE_DISK_CACHE_TEST_BASE_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/macros.h"
+#include "base/test/scoped_async_task_scheduler.h"
 #include "base/threading/thread.h"
 #include "net/base/cache_type.h"
 #include "net/disk_cache/disk_cache.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
 namespace net {
 
 class IOBuffer;
 
@@ skipping 24 matching lines @@
   // Deletes the contents of |cache_path_|.
   bool CleanupCacheDir();
 
   void TearDown() override;
 
   base::FilePath cache_path_;
 
  private:
   base::ScopedTempDir temp_dir_;
   std::unique_ptr<base::MessageLoop> message_loop_;
+
+  // Use a ScopedAsyncTaskScheduler instead of a ScopedTaskScheduler to allow
+  // disk_cache::InFlightIO::WaitForPendingIO to wait for TaskScheduler tasks
+  // from the main thread using WaitableEvents (this wouldn't work if
+  // TaskScheduler tasks ran on the main thread).
+  base::test::ScopedAsyncTaskScheduler scoped_async_task_scheduler_;
 };
 
 // Provides basic support for cache related tests.
 class DiskCacheTestWithCache : public DiskCacheTest {
  protected:
   class TestIterator {
    public:
     explicit TestIterator(
         std::unique_ptr<disk_cache::Backend::Iterator> iterator);
     ~TestIterator();
@@ skipping 117 matching lines @@
 
  private:
   void InitMemoryCache();
   void InitDiskCache();
 
   base::Thread cache_thread_;
   DISALLOW_COPY_AND_ASSIGN(DiskCacheTestWithCache);
 };
 
 #endif  // NET_DISK_CACHE_DISK_CACHE_TEST_BASE_H_