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

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/strings/string_util.h"
 #include "base/strings/stringprintf.h"
@@ skipping 3126 matching lines @@
   cache_->OnExternalCacheHit("key0");
 
   TrimForTest(false);
 
   // Make sure the older key remains.
   EXPECT_EQ(1, cache_->GetEntryCount());
   ASSERT_EQ(net::OK, OpenEntry("key0", &entry));
   entry->Close();
 }
 
-// The Simple Cache backend requires a few guarantees from the filesystem like
-// atomic renaming of recently open files. Those guarantees are not provided in
-// general on Windows.
-#if defined(OS_POSIX)
-
 TEST_F(DiskCacheBackendTest, SimpleCacheShutdownWithPendingCreate) {
   SetCacheType(net::APP_CACHE);
   SetSimpleCacheMode();
   BackendShutdownWithPendingCreate(false);
 }
 
 TEST_F(DiskCacheBackendTest, SimpleCacheShutdownWithPendingFileIO) {
   SetCacheType(net::APP_CACHE);
   SetSimpleCacheMode();
   BackendShutdownWithPendingFileIO(false);
@@ skipping 318 matching lines @@
   scoped_ptr<TestIterator> iter = CreateIterator();
   disk_cache::Entry* entry = NULL;
   ASSERT_EQ(net::OK, iter->OpenNextEntry(&entry));
   EXPECT_TRUE(entry);
   disk_cache::ScopedEntryPtr entry_closer(entry);
 
   cache_.reset();
   // This test passes if we don't leak memory.
 }
 
-#endif  // defined(OS_POSIX)
+// Tests that a SimpleCache doesn't crash when files are deleted very quickly
+// 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());
+  }
+}