Make InputMethodEngine to inherit from new added class InputMethodEngineBase.

chrome/chrome_browser.gypi

 # Copyright 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': {
     # All .cc, .h, .m, and .mm files under browser except for:
     # * tests and mocks.
     # * code below browser/chromeos
     # * code below browser/extensions
@@ skipping 961 matching lines @@
     ],
     # ChromeOS-sources not ending in _chromeos (which would be included in
     # other sections and filtered out for non-ChromeOS platforms.
     'chrome_browser_chromeos_sources': [
       'browser/download/notification/download_item_notification.cc',
       'browser/download/notification/download_item_notification.h',
       'browser/download/notification/download_notification.cc',
       'browser/download/notification/download_notification.h',
       'browser/download/notification/download_notification_manager.cc',
       'browser/download/notification/download_notification_manager.h',
+      'browser/input_method/input_method_engine_base.cc',
+      'browser/input_method/input_method_engine_base.h',
       'browser/media/protected_media_identifier_permission_context.cc',
       'browser/media/protected_media_identifier_permission_context.h',
       'browser/media/protected_media_identifier_permission_context_factory.cc',
       'browser/media/protected_media_identifier_permission_context_factory.h',
       'browser/metrics/chromeos_metrics_provider.cc',
       'browser/metrics/chromeos_metrics_provider.h',
       'browser/metrics/perf/cpu_identity.cc',
       'browser/metrics/perf/cpu_identity.h',
       'browser/metrics/perf/random_selector.cc',
       'browser/metrics/perf/random_selector.h',
@@ skipping 2597 matching lines @@
           ],
         }],
         ['chromeos==1', {
           'sources': [
             '<@(chrome_browser_chromeos_sources)',
 
             # This file is generated by GRIT.
             '<(SHARED_INTERMEDIATE_DIR)/ui/chromeos/resources/grit/ui_chromeos_resources_map.cc',
           ],
           'dependencies': [
+            '../base/base.gyp:base',
             'browser_chromeos',
             '../components/components.gyp:user_manager',
             '../ui/chromeos/ui_chromeos.gyp:ui_chromeos_resources',
+            '../ui/base/ime/ui_base_ime.gyp:ui_base_ime',
+            '../ui/base/ui_base.gyp:ui_base',
+            '../ui/events/events.gyp:dom_keycode_converter',
           ],
         }],
         ['use_cups==1', {
           'dependencies': [
             '../printing/printing.gyp:cups',
           ],
         }],
         ['use_gnome_keyring==1', {
           'sources': [ '<@(chrome_browser_gnome_keyring_sources)' ],
           'dependencies': [
@@ skipping 577 matching lines @@
             '../components/components.gyp:omnibox_browser',
             '../components/components.gyp:rlz',
             '../components/components.gyp:search_engines',
             '../rlz/rlz.gyp:rlz_lib',
           ],
         },
       ],
     }],
   ],
 }