Allow overriding Chromium-branded Android resources.

chrome/chrome.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,
 
     # Define the common dependencies that contain all the actual
     # Chromium functionality.  This list gets pulled in below by
     # the link of the actual chrome (or chromium) executable on
@@ skipping 601 matching lines @@
             '../third_party/android_tools/android_tools.gyp:android_support_v7_appcompat_javalib',
             '../third_party/android_tools/android_tools.gyp:android_support_v7_mediarouter_javalib',
             '../third_party/android_tools/android_tools.gyp:android_support_v7_recyclerview_javalib',
             '../third_party/android_tools/android_tools.gyp:android_support_v13_javalib',
             '../third_party/android_tools/android_tools.gyp:google_play_services_javalib',
             '../third_party/cacheinvalidation/cacheinvalidation.gyp:cacheinvalidation_javalib',
             '../third_party/jsr-305/jsr-305.gyp:jsr_305_javalib',
             '../ui/android/ui_android.gyp:ui_java',
           ],
           'variables': {
+            'variables': {
+              'android_branding_res_dirs%': ['<(java_in_dir)/res_chromium'],
+            },
             'java_in_dir': '../chrome/android/java',
             'has_java_resources': 1,
             'R_package': 'org.chromium.chrome',
             'R_package_relpath': 'org/chromium/chrome',
             # Include channel-specific resources and xml string files generated
             # from generated_resources.grd
-            'res_channel_dir': '<(java_in_dir)/res_default',
             'res_extra_dirs': [
-              '<(res_channel_dir)',
+              '<@(android_branding_res_dirs)',
               '<(SHARED_INTERMEDIATE_DIR)/chrome/java/res',
             ],
             'res_extra_files': [
-              '<!@(find <(res_channel_dir) -type f)',
+              '<!@(find <(android_branding_res_dirs) -type f)',
               '<!@pymod_do_main(grit_info <@(grit_defines) --outputs "<(SHARED_INTERMEDIATE_DIR)/chrome" app/generated_resources.grd)',
             ],
           },
           'conditions': [
             ['configuration_policy != 1', {
               'dependencies!': [
                 '../components/components.gyp:app_restrictions_resources',
               ],
             }],
           ],
@@ skipping 186 matching lines @@
                   '<(DEPTH)/third_party/kasko'
                 ],
               },
             },
           },
         },
       ],
     }],
   ],  # 'conditions'
 }