Update from https://crrev.com/308331

net/disk_cache/backend_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 "base/basictypes.h"
 #include "base/files/file_util.h"
 #include "base/metrics/field_trial.h"
 #include "base/port.h"
+#include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
 #include "base/thread_task_runner_handle.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "net/base/cache_type.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/base/test_completion_callback.h"
@@ skipping 3256 matching lines @@
   entry->Close();
   entry = NULL;
 
   // To make sure the file creation completed we need to call open again so that
   // we block until it actually created the files.
   ASSERT_EQ(net::OK, OpenEntry(key, &entry));
   ASSERT_NE(null, entry);
   entry->Close();
   entry = NULL;
 
+  // The entry is being closed on the Simple Cache worker pool
+  disk_cache::SimpleBackendImpl::FlushWorkerPoolForTesting();
+  base::RunLoop().RunUntilIdle();
+
   // Write an invalid header for stream 0 and stream 1.
   base::FilePath entry_file1_path = cache_path_.AppendASCII(
       disk_cache::simple_util::GetFilenameFromKeyAndFileIndex(key, 0));
 
   disk_cache::SimpleFileHeader header;
   header.initial_magic_number = GG_UINT64_C(0xbadf00d);
   EXPECT_EQ(
       implicit_cast<int>(sizeof(header)),
       base::WriteFile(entry_file1_path, reinterpret_cast<char*>(&header),
                            sizeof(header)));
@@ skipping 191 matching lines @@
 // after closing.
 // NOTE: IF THIS TEST IS FLAKY THEN IT IS FAILING. See https://crbug.com/416940
 TEST_F(DiskCacheBackendTest, SimpleCacheDeleteQuickly) {
   SetSimpleCacheMode();
   for (int i = 0; i < 100; ++i) {
     InitCache();
     cache_.reset();
     EXPECT_TRUE(CleanupCacheDir());
   }
 }