base: Remove now-unused MessagePumpObserver.

base/base.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,
   },
   'includes': [
     '../build/win_precompile.gypi',
@@ skipping 221 matching lines @@
         'event_recorder_stubs.cc',
         'event_recorder_win.cc',
         'linux_util.cc',
         'linux_util.h',
         'message_loop/message_pump_android.cc',
         'message_loop/message_pump_android.h',
         'message_loop/message_pump_glib.cc',
         'message_loop/message_pump_glib.h',
         'message_loop/message_pump_io_ios.cc',
         'message_loop/message_pump_io_ios.h',
-        'message_loop/message_pump_observer.h',
         'message_loop/message_pump_libevent.cc',
         'message_loop/message_pump_libevent.h',
         'message_loop/message_pump_mac.h',
         'message_loop/message_pump_mac.mm',
         'metrics/field_trial.cc',
         'metrics/field_trial.h',
         'posix/file_descriptor_shuffle.cc',
         'posix/file_descriptor_shuffle.h',
         'sync_socket.h',
         'sync_socket_win.cc',
@@ skipping 867 matching lines @@
             'async_socket_io_handler_posix.cc',
             'async_socket_io_handler_win.cc',
             'auto_reset.h',
             'event_recorder.h',
             'event_recorder_stubs.cc',
             'event_recorder_win.cc',
             'linux_util.cc',
             'linux_util.h',
             'md5.cc',
             'md5.h',
-            'message_loop/message_pump_observer.h',
             'message_loop/message_pump_libevent.cc',
             'message_loop/message_pump_libevent.h',
             'metrics/field_trial.cc',
             'metrics/field_trial.h',
             'posix/file_descriptor_shuffle.cc',
             'posix/file_descriptor_shuffle.h',
             'sync_socket.h',
             'sync_socket_win.cc',
             'sync_socket_posix.cc',
           ],
@@ skipping 361 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],
 }