Revert 175073 because it fails to compile on Linux.

device/device.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 133 matching lines @@
         ['chromeos==1', {
           'dependencies': [
             '../build/linux/system.gyp:dbus',
             '../chromeos/chromeos.gyp:chromeos_test_support',
             '../dbus/dbus.gyp:dbus',
           ]
         }],
       ],
     },
   ],
-  'conditions': [
-    ['OS=="linux"', {
-      'targets': [
-        {
-          # Protobuf compiler / generator for the MtpFileEntry and
-          # MtpFileEntries protocol buffers.
-          'target_name': 'mtp_file_entry_proto',
-          'type': 'static_library',
-          'sources': [
-            '../third_party/cros_system_api/dbus/mtp_file_entry.proto',
-          ],
-          'variables': {
-            'proto_in_dir': '../third_party/cros_system_api/dbus',
-            'proto_out_dir': 'device/media_transfer_protocol',
-          },
-          'includes': ['../build/protoc.gypi'],
-        },
-        {
-          # Protobuf compiler / generator for the MtpStorageInfo protocol
-          # buffer.
-          'target_name': 'mtp_storage_info_proto',
-          'type': 'static_library',
-          'sources': [
-            '../third_party/cros_system_api/dbus/mtp_storage_info.proto',
-          ],
-          'variables': {
-            'proto_in_dir': '../third_party/cros_system_api/dbus',
-            'proto_out_dir': 'device/media_transfer_protocol',
-          },
-          'includes': ['../build/protoc.gypi'],
-        },
-        {
-          'target_name': 'device_media_transfer_protocol',
-          'type': 'static_library',
-          'dependencies': [
-            '../build/linux/system.gyp:dbus',
-            'mtp_file_entry_proto',
-            'mtp_storage_info_proto',
-          ],

[Ryan Sleevi, 2013/01/04 01:51:45]

The root issue for the failure is here. static_library targets are allowed to
concurrently build, unless they're marked hard_dependency OR one of their
dependencies has exported a dependency (export_dependent_settings) on a
hard_dependency.

You have two solutions, depending on how you want your "public" API to be:
1) export_dependent_settings the two _proto targets here. This is primarily
intended when one of YOUR public headers (_manager.h, _daemon_client.h) include
the .pb.h
2) In all targets that directly #include the .pb.h , add dependencies to the
_proto targets

I believe that in this case, #2 is more correct, and the dependency should be
expressed in chrome/chrome_browser.gypi, since those are the files that are
directly including those targets. We try to keep the dependencies close to their
targets, rather than by spooky-action-at-a-distance. That way, it's clear
if/when the dependencies can be removed, whereas export_dependent_settings-ing
it, it won't be clear if and when the dependency on the _protos can be removed.

-          'sources': [
-            'media_transfer_protocol/media_transfer_protocol_daemon_client.cc',
-            'media_transfer_protocol/media_transfer_protocol_daemon_client.h',
-            'media_transfer_protocol/media_transfer_protocol_manager.cc',
-            'media_transfer_protocol/media_transfer_protocol_manager.h',
-          ],
-        },
-      ],
-    }],
-  ],
 }