Allow overriding Chromium-branded Android resources.

chrome/chrome.gyp

Index: chrome/chrome.gyp
diff --git a/chrome/chrome.gyp b/chrome/chrome.gyp
index c3e21bc223dfdaac979f1fec7d6d49c96c3f7577..04f7fe7b523177b216e687d7a47fbafe8d6e7be5 100644
--- a/chrome/chrome.gyp
+++ b/chrome/chrome.gyp
@@ -619,19 +619,21 @@
             '../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)',
             ],
           },