[fsp] Add support for truncating files.

chrome/browser/chromeos/file_system_provider/operations/truncate.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 "chrome/browser/chromeos/file_system_provider/operations/create_file.h"
+#include "chrome/browser/chromeos/file_system_provider/operations/truncate.h"
 
 #include <string>
 
 #include "chrome/common/extensions/api/file_system_provider.h"
 #include "chrome/common/extensions/api/file_system_provider_internal.h"
 
 namespace chromeos {
 namespace file_system_provider {
 namespace operations {
 
-CreateFile::CreateFile(extensions::EventRouter* event_router,
-                       const ProvidedFileSystemInfo& file_system_info,
-                       const base::FilePath& file_path,
-                       const fileapi::AsyncFileUtil::StatusCallback& callback)
+Truncate::Truncate(extensions::EventRouter* event_router,
+                   const ProvidedFileSystemInfo& file_system_info,
+                   const base::FilePath& file_path,
+                   int64 length,
+                   const fileapi::AsyncFileUtil::StatusCallback& callback)
     : Operation(event_router, file_system_info),
       file_path_(file_path),
+      length_(length),
       callback_(callback) {
 }
 
-CreateFile::~CreateFile() {
+Truncate::~Truncate() {
 }
 
-bool CreateFile::Execute(int request_id) {
+bool Truncate::Execute(int request_id) {
   scoped_ptr<base::DictionaryValue> values(new base::DictionaryValue);
   values->SetString("filePath", file_path_.AsUTF8Unsafe());
+  values->SetDouble("length", length_);
 
   return SendEvent(
       request_id,
-      extensions::api::file_system_provider::OnCreateFileRequested::kEventName,
+      extensions::api::file_system_provider::OnTruncateRequested::kEventName,
       values.Pass());
 }
 
-void CreateFile::OnSuccess(int /* request_id */,
-                           scoped_ptr<RequestValue> /* result */,
-                           bool has_more) {
+void Truncate::OnSuccess(int /* request_id */,
+                         scoped_ptr<RequestValue> /* result */,
+                         bool has_more) {
   callback_.Run(base::File::FILE_OK);
 }
 
-void CreateFile::OnError(int /* request_id */,
-                         scoped_ptr<RequestValue> /* result */,
-                         base::File::Error error) {
+void Truncate::OnError(int /* request_id */,
+                       scoped_ptr<RequestValue> /* result */,
+                       base::File::Error error) {
   callback_.Run(error);
 }
 
 }  // namespace operations
 }  // namespace file_system_provider
 }  // namespace chromeos