Remove implicit conversions from scoped_refptr to T* in c/b/chromeos/file*

chrome/browser/chromeos/file_system_provider/fileapi/file_stream_writer.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/fileapi/file_stream_writer.h"
 
 #include "base/debug/trace_event.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/chromeos/file_system_provider/fileapi/provider_async_file_util.h"
 #include "chrome/browser/chromeos/file_system_provider/mount_path_util.h"
@@ skipping 67 matching lines @@
     if (!file_system_.get()) {
       BrowserThread::PostTask(
           BrowserThread::IO,
           FROM_HERE,
           base::Bind(callback, base::File::FILE_ERROR_ABORT));
       return;
     }
 
     abort_callback_ = file_system_->WriteFile(
         file_handle_,
-        buffer,
+        buffer.get(),
         offset,
         length,
         base::Bind(
             &OperationRunner::OnWriteFileCompletedOnUIThread, this, callback));
   }
 
   // Aborts the most recent operation (if exists), and calls the callback.
   void AbortOnUIThread(const storage::AsyncFileUtil::StatusCallback& callback) {
     DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
@@ skipping 230 matching lines @@
                  current_offset_,
                  buffer_length,
                  base::Bind(&FileStreamWriter::OnWriteFileCompleted,
                             weak_ptr_factory_.GetWeakPtr(),
                             buffer_length,
                             callback)));
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos