Rename app_strings to ui_strings.

ui/base/strings/ui_strings.gyp

 {
   'variables': {
     'chromium_code': 1,
     'grit_base_out_dir': '<(SHARED_INTERMEDIATE_DIR)/ui',
   },
   'targets': [
     {
       'target_name': 'ui_strings',
       'type': 'none',
       'actions': [
         {
-          'action_name': 'app_strings',
+          'action_name': 'ui_strings',
           'variables': {
-            'grit_grd_file': 'app_strings.grd',
-            'grit_out_dir': '<(grit_base_out_dir)/app_strings',
+            'grit_grd_file': 'ui_strings.grd',
+            'grit_out_dir': '<(grit_base_out_dir)/ui_strings',
           },
           'includes': [ '../../../build/grit_action.gypi' ],
         },
         {
           'action_name': 'app_locale_settings',
           'variables': {
             'grit_grd_file': 'app_locale_settings.grd',
             'grit_out_dir': '<(grit_base_out_dir)/app_locale_settings',
           },
           'includes': [ '../../../build/grit_action.gypi' ],
         },
       ],
       'direct_dependent_settings': {
         'include_dirs': [
           '<(grit_base_out_dir)/app_locale_settings',
-          '<(grit_base_out_dir)/app_strings',
+          '<(grit_base_out_dir)/ui_strings',
         ],
       },
       'conditions': [
         ['OS=="win"', {
           'dependencies': ['../../../build/win/system.gyp:cygwin'],
         }],
       ],
     },
   ],
   'conditions': [
     ['os_posix == 1 and OS != "mac"', {
       'targets': [{
         'target_name': 'ui_unittest_strings',
         'type': 'none',
         'variables': {
           'repack_path': '<(DEPTH)/tools/data_pack/repack.py',
         },
         'actions': [
           {
             'action_name': 'repack_ui_unittest_strings',
             'variables': {
               'pak_inputs': [
-                '<(grit_base_out_dir)/app_strings/app_strings_en-US.pak',
+                '<(grit_base_out_dir)/ui_strings/ui_strings_en-US.pak',
                 '<(grit_base_out_dir)/app_locale_settings/app_locale_settings_en-US.pak',
               ],
             },
             'inputs': [
               '<(repack_path)',
               '<@(pak_inputs)',
             ],
             'outputs': [
               '<(PRODUCT_DIR)/app_unittests_strings/en-US.pak',
             ],
             'action': ['python', '<(repack_path)', '<@(_outputs)',
                        '<@(pak_inputs)'],
           },
         ],
         'copies': [
           {
             'destination': '<(PRODUCT_DIR)/app_unittests_strings',
             'files': [
               '<(grit_base_out_dir)/ui_resources/ui_resources.pak',
             ],
           },
         ],
       }],
     }],
   ],
 }