Remove MTP support on Linux.

components/storage_monitor/storage_monitor_chromeos.h

 // 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.
 
 // StorageMonitorCros listens for mount point changes and notifies listeners
 // about the addition and deletion of media devices. This class lives on the
 // UI thread.
 
 #ifndef COMPONENTS_STORAGE_MONITOR_STORAGE_MONITOR_CHROMEOS_H_
 #define COMPONENTS_STORAGE_MONITOR_STORAGE_MONITOR_CHROMEOS_H_
 
 #if !defined(OS_CHROMEOS)
 #error "Should only be used on ChromeOS."
 #endif
 
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "build/build_config.h"
 #include "chromeos/disks/disk_mount_manager.h"
 #include "components/storage_monitor/storage_monitor.h"
 
 namespace storage_monitor {
 
-class MediaTransferProtocolDeviceObserverLinux;
+class MediaTransferProtocolDeviceObserverChromeOS;
 
 class StorageMonitorCros : public StorageMonitor,
                            public chromeos::disks::DiskMountManager::Observer {
  public:
   // Should only be called by browser start up code.
   // Use StorageMonitor::GetInstance() instead.
   StorageMonitorCros();
   ~StorageMonitorCros() override;
 
   // Sets up disk listeners and issues notifications for any discovered
@@ skipping 39 matching lines @@
   // a DCIM folder.
   void AddMountedPath(
       const chromeos::disks::DiskMountManager::MountPointInfo& mount_info,
       bool has_dcim);
 
   // Mapping of relevant mount points and their corresponding mount devices.
   MountMap mount_map_;
 
   std::unique_ptr<device::MediaTransferProtocolManager>
       media_transfer_protocol_manager_;
-  std::unique_ptr<MediaTransferProtocolDeviceObserverLinux>
+  std::unique_ptr<MediaTransferProtocolDeviceObserverChromeOS>
       media_transfer_protocol_device_observer_;
 
   base::WeakPtrFactory<StorageMonitorCros> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(StorageMonitorCros);
 };
 
 }  // namespace storage_monitor
 
 #endif  // COMPONENTS_STORAGE_MONITOR_STORAGE_MONITOR_CHROMEOS_H_