Update from chromium https://crrev.com/302282

net/disk_cache/simple/simple_util_win.cc

+// Copyright 2014 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 "net/disk_cache/simple/simple_util.h"
+
+#include <windows.h>
+
+#include "base/files/file_util.h"
+#include "base/format_macros.h"
+#include "base/rand_util.h"
+#include "base/strings/stringprintf.h"
+#include "net/disk_cache/cache_util.h"
+
+namespace disk_cache {
+namespace simple_util {
+
+bool SimpleCacheDeleteFile(const base::FilePath& path) {
+  // Even if a file was opened with FLAG_SHARE_DELETE, it is not possible to
+  // create a new file with the same name until the original file is actually
+  // deleted. To allow new files to be created with the new name right away,
+  // the file is renamed before it is deleted.
+
+  // Why a random name? Because if the name was derived from our original name,
+  // then churn on a particular cache entry could cause flakey behaviour.
+
+  // TODO(gaivnp): Ensure these "todelete_" files are cleaned up on periodic
+  // directory sweeps.
+  const base::FilePath rename_target =
+      path.DirName().AppendASCII(base::StringPrintf("todelete_%016" PRIx64,
+                                                    base::RandUint64()));
+
+  bool rename_succeeded = !!MoveFile(path.value().c_str(),
+                                     rename_target.value().c_str());
+  if (rename_succeeded)
+    return DeleteCacheFile(rename_target);
+
+  // The rename did not succeed. The fallback behaviour is to delete the file in
+  // place, which might cause some flake.
+  return DeleteCacheFile(path);
+}
+
+}  // namespace simple_util
+}  // namespace disk_cache