Revert "Updating the mapped_file_avoid_mmap_posix implementation."

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/file_util.h"
 #include "base/port.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/third_party/dynamic_annotations/dynamic_annotations.h"
@@ skipping 2741 matching lines @@
 
   EXPECT_FALSE(cache_impl_->IsAllocAllowed(0, kOneMB));
 }
 
 // Tests that sharing of external files works and we are able to delete the
 // files when we need to.
 TEST_F(DiskCacheBackendTest, FileSharing) {
   InitCache();
 
   disk_cache::Addr address(0x80000001);
-
-  RunTaskForTest(base::Bind(
-      base::IgnoreResult(&disk_cache::BackendImpl::CreateExternalFile),
-      base::Unretained(cache_impl_),
-      &address));
+  ASSERT_TRUE(cache_impl_->CreateExternalFile(&address));
   base::FilePath name = cache_impl_->GetFileName(address);
 
   scoped_refptr<disk_cache::File> file(new disk_cache::File(false));
   file->Init(name);
 
 #if defined(OS_WIN)
   DWORD sharing = FILE_SHARE_READ | FILE_SHARE_WRITE;
   DWORD access = GENERIC_READ | GENERIC_WRITE;
   base::win::ScopedHandle file2(CreateFile(
       name.value().c_str(), access, sharing, NULL, OPEN_EXISTING, 0, NULL));
@@ skipping 286 matching lines @@
   delete cache;
   DisableIntegrityCheck();
 }
 
 TEST_F(DiskCacheBackendTest, SimpleCacheFixEnumerators) {
   SetSimpleCacheMode();
   BackendFixEnumerators();
 }
 
 #endif  // !defined(OS_WIN)