Run input_method_bridge_unittest on Mac, remove unused DummyInputMethodDelegate

ui/base/ime/ui_base_ime.gyp

 # Copyright 2015 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 55 matching lines @@
         'chromeos/mock_ime_candidate_window_handler.h',
         'chromeos/mock_ime_engine_handler.cc',
         'chromeos/mock_ime_engine_handler.h',
         'chromeos/mock_ime_input_context_handler.cc',
         'chromeos/mock_ime_input_context_handler.h',
         'composition_text.cc',
         'composition_text.h',
         'composition_text_util_pango.cc',
         'composition_text_util_pango.h',
         'composition_underline.h',
-        'dummy_input_method_delegate.cc',
-        'dummy_input_method_delegate.h',
         'infolist_entry.cc',
         'infolist_entry.h',
         'input_method.h',
         'input_method_auralinux.cc',
         'input_method_auralinux.h',
         'input_method_base.cc',
         'input_method_base.h',
         'input_method_chromeos.cc',
         'input_method_chromeos.h',
         'input_method_delegate.h',
@@ skipping 87 matching lines @@
         ['use_x11==0', {
           'sources!': [
             'composition_text_util_pango.cc',
             'composition_text_util_pango.h',
           ],
         }],
       ],
     },
   ],
 }