Remove stray platform_file.h from content

content/child/fileapi/webfilewriter_impl.cc

 // Copyright 2013 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 "content/child/fileapi/webfilewriter_impl.h"
 
 #include "base/bind.h"
-#include "base/platform_file.h"
 #include "base/synchronization/waitable_event.h"
 #include "content/child/child_thread.h"
 #include "content/child/fileapi/file_system_dispatcher.h"
 #include "content/child/worker_task_runner.h"
 
 namespace content {
 
 namespace {
 
 FileSystemDispatcher* GetFileSystemDispatcher() {
@@ skipping 136 matching lines @@
     DCHECK(!bridge_->waitable_event());
     closure.Run();
     return;
   }
   main_thread_loop_->PostTask(FROM_HERE, closure);
   if (bridge_->waitable_event())
     bridge_->WaitAndRun();
 }
 
 }  // namespace content