Remove MTP support on Linux.

components/storage_monitor/storage_monitor.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.
 
 #ifndef COMPONENTS_STORAGE_MONITOR_STORAGE_MONITOR_H_
 #define COMPONENTS_STORAGE_MONITOR_STORAGE_MONITOR_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 102 matching lines @@
   // On success, returns true and fills in |device_location| with device
   // interface details and |storage_object_id| with the string ID that
   // uniquely identifies the object on the device. This ID need not be
   // persistent across sessions.
   virtual bool GetMTPStorageInfoFromDeviceId(
       const std::string& storage_device_id,
       base::string16* device_location,
       base::string16* storage_object_id) const = 0;
 #endif
 
-#if defined(OS_LINUX)
+#if defined(OS_CHROMEOS)
   virtual device::MediaTransferProtocolManager*
       media_transfer_protocol_manager() = 0;
 #endif
 
   // Returns information for all known storages on the system,
   // including fixed and removable storages.
   std::vector<StorageInfo> GetAllAvailableStorages() const;
 
   void AddObserver(RemovableStorageObserver* obs);
   void RemoveObserver(RemovableStorageObserver* obs);
@@ skipping 52 matching lines @@
 
   // Map of all known storage devices,including fixed and removable storages.
   StorageMap storage_map_;
 
   std::unique_ptr<TransientDeviceIds> transient_device_ids_;
 };
 
 }  // namespace storage_monitor
 
 #endif  // COMPONENTS_STORAGE_MONITOR_STORAGE_MONITOR_H_