Media Galleries: Access MTP devices by file ids rather than file paths.

chrome/browser/media_galleries/linux/mtp_read_file_worker.cc

 // 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.
 
 #include "chrome/browser/media_galleries/linux/mtp_read_file_worker.h"
 
 #include "base/bind.h"
 #include "base/file_util.h"
 #include "base/files/file_path.h"
 #include "base/numerics/safe_conversions.h"
@@ skipping 48 matching lines @@
     scoped_ptr<SnapshotFileDetails> snapshot_file_details) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
   DCHECK(snapshot_file_details.get());
 
   // To avoid calling |snapshot_file_details| methods and passing ownership of
   // |snapshot_file_details| in the same_line.
   SnapshotFileDetails* snapshot_file_details_ptr = snapshot_file_details.get();
 
   device::MediaTransferProtocolManager* mtp_device_manager =
       StorageMonitor::GetInstance()->media_transfer_protocol_manager();
-  mtp_device_manager->ReadFileChunkByPath(
+  mtp_device_manager->ReadFileChunkById(
       device_handle_,
-      snapshot_file_details_ptr->device_file_path(),
+      snapshot_file_details_ptr->file_id(),
       snapshot_file_details_ptr->bytes_written(),
       snapshot_file_details_ptr->BytesToRead(),
       base::Bind(&MTPReadFileWorker::OnDidReadDataChunkFromDeviceFile,
                  weak_ptr_factory_.GetWeakPtr(),
                  base::Passed(&snapshot_file_details)));
 }
 
 void MTPReadFileWorker::OnDidReadDataChunkFromDeviceFile(
     scoped_ptr<SnapshotFileDetails> snapshot_file_details,
     const std::string& data,
@@ skipping 50 matching lines @@
                    base::File::FILE_ERROR_FAILED));
     return;
   }
   content::BrowserThread::PostTask(
       content::BrowserThread::IO,
       FROM_HERE,
       base::Bind(snapshot_file_details->success_callback(),
                  snapshot_file_details->file_info(),
                  snapshot_file_details->snapshot_file_path()));
 }