Revert "Updating the mapped_file_avoid_mmap_posix implementation."

net/disk_cache/disk_cache_test_util.cc

 // Copyright (c) 2011 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/disk_cache_test_util.h"
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop_proxy.h"
 #include "base/path_service.h"
@@ skipping 24 matching lines @@
   for (size_t i = 0; i < len; i++) {
     buffer[i] = static_cast<char>(rand());
     if (!buffer[i] && no_nulls)
       buffer[i] = 'g';
   }
   if (len && !buffer[0])
     buffer[0] = 'g';
 }
 
 bool CreateCacheTestFile(const base::FilePath& name) {
-  return CreateCacheTestFileWithSize(name, 4 * 1024 * 1024);
-}
-
-bool CreateCacheTestFileWithSize(const base::FilePath& name, size_t size){
   int flags = base::PLATFORM_FILE_CREATE_ALWAYS |
               base::PLATFORM_FILE_READ |
               base::PLATFORM_FILE_WRITE;
 
   scoped_refptr<disk_cache::File> file(new disk_cache::File(
       base::CreatePlatformFile(name, flags, NULL, NULL)));
   if (!file->IsValid())
     return false;
 
-  file->SetLength(size);
+  file->SetLength(4 * 1024 * 1024);
   return true;
 }
 
 bool DeleteCache(const base::FilePath& path) {
   disk_cache::DeleteCache(path, false);
   return true;
 }
 
 bool CheckCacheIntegrity(const base::FilePath& path, bool new_eviction,
                          uint32 mask) {
@@ skipping 72 matching lines @@
 
   if (reuse_) {
     DCHECK_EQ(1, reuse_);
     if (2 == reuse_)
       helper_->set_callback_reused_error(true);
     reuse_++;
   }
 
   helper_->CallbackWasCalled();
 }