Convert drive::FileWriteHelper to a single function for simplification.

chrome/chrome_browser_chromeos.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'browser_chromeos',
       'type': 'static_library',
@@ skipping 257 matching lines @@
         'browser/chromeos/drive/file_system_backend_delegate.cc',
         'browser/chromeos/drive/file_system_backend_delegate.h',
         'browser/chromeos/drive/file_system_interface.h',
         'browser/chromeos/drive/file_system_metadata.cc',
         'browser/chromeos/drive/file_system_metadata.h',
         'browser/chromeos/drive/file_system_observer.h',
         'browser/chromeos/drive/file_system_util.cc',
         'browser/chromeos/drive/file_system_util.h',
         'browser/chromeos/drive/file_task_executor.cc',
         'browser/chromeos/drive/file_task_executor.h',
-        'browser/chromeos/drive/file_write_helper.cc',
-        'browser/chromeos/drive/file_write_helper.h',
         'browser/chromeos/drive/file_write_watcher.cc',
         'browser/chromeos/drive/file_write_watcher.h',
         'browser/chromeos/drive/fileapi_worker.cc',
         'browser/chromeos/drive/fileapi_worker.h',
         'browser/chromeos/drive/job_list.cc',
         'browser/chromeos/drive/job_list.h',
         'browser/chromeos/drive/job_queue.cc',
         'browser/chromeos/drive/job_queue.h',
         'browser/chromeos/drive/job_scheduler.cc',
         'browser/chromeos/drive/job_scheduler.h',
@@ skipping 10 matching lines @@
         'browser/chromeos/drive/resource_metadata_storage.cc',
         'browser/chromeos/drive/resource_metadata_storage.h',
         'browser/chromeos/drive/search_metadata.cc',
         'browser/chromeos/drive/search_metadata.h',
         'browser/chromeos/drive/sync_client.cc',
         'browser/chromeos/drive/sync_client.h',
         'browser/chromeos/drive/webkit_file_stream_reader_impl.cc',
         'browser/chromeos/drive/webkit_file_stream_reader_impl.h',
         'browser/chromeos/drive/webkit_file_stream_writer_impl.cc',
         'browser/chromeos/drive/webkit_file_stream_writer_impl.h',
+        'browser/chromeos/drive/write_on_cache_file.cc',
+        'browser/chromeos/drive/write_on_cache_file.h',
         'browser/chromeos/enrollment_dialog_view.cc',
         'browser/chromeos/enrollment_dialog_view.h',
         'browser/chromeos/enterprise_extension_observer.cc',
         'browser/chromeos/enterprise_extension_observer.h',
         'browser/chromeos/extensions/default_app_order.cc',
         'browser/chromeos/extensions/default_app_order.h',
         'browser/chromeos/extensions/echo_private_api.cc',
         'browser/chromeos/extensions/echo_private_api.h',
         'browser/chromeos/extensions/external_cache.cc',
         'browser/chromeos/extensions/external_cache.h',
@@ skipping 649 matching lines @@
         'browser/chromeos/attestation/attestation_key_payload.proto',
       ],
       'variables': {
         'proto_in_dir': 'browser/chromeos/attestation',
         'proto_out_dir': 'chrome/browser/chromeos/attestation',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }