Use the variable "branding_path_component" to locate brand-specific files and resources in installer

chrome/installer/mini_installer.gyp

 {
   'variables': {
     'version_py': '<(DEPTH)/build/util/version.py',
     'version_path': '../../chrome/VERSION',
     'lastchange_path': '<(DEPTH)/build/util/LASTCHANGE',
-    # 'branding_dir' is set in the 'conditions' section at the bottom.
+    'branding_dir': '../app/theme/<(branding_path_component)',
     'msvs_use_common_release': 0,
     'msvs_use_common_linker_extras': 0,
     'mini_installer_internal_deps%': 0,
     'mini_installer_official_deps%': 0,
   },
   'includes': [
     '../../build/win_precompile.gypi',
   ],
   'conditions': [
     ['OS=="win"', {
@@ skipping 274 matching lines @@
                 #'--distribution=$(CHROMIUM_BUILD)',
                 '--distribution=_google_chrome',
                 # Optional arguments to generate diff installer
                 #'--last_chrome_installer=C:/Temp/base',
                 #'--setup_exe_format=DIFF',
                 #'--diff_algorithm=COURGETTE',
               ],
               'message': 'Create installer archive',
             },
           ],
-          # TODO(mark):  <(branding_dir) should be defined by the
-          # global condition block at the bottom of the file, but
-          # this doesn't work due to the following issue:
-          #
-          #   http://code.google.com/p/gyp/issues/detail?id=22
-          #
-          # Remove this block once the above issue is fixed.
-          'conditions': [
-            [ 'branding == "Chrome"', {
-              'variables': {
-                 'branding_dir': '../app/theme/google_chrome',
-              },
-            }, { # else branding!="Chrome"
-              'variables': {
-                 'branding_dir': '../app/theme/chromium',
-              },
-            }],
-          ],
         },
       ],
       'conditions': [
         ['test_isolation_mode != "noop"', {
           'targets': [
             {
               'target_name': 'mini_installer_tests_run',
               'type': 'none',
               'dependencies': [
                 'mini_installer',
               ],
               'includes': [
                 '../../build/isolate.gypi',
               ],
               'sources': [
                 'mini_installer_tests.isolate',
               ],
             },
           ],
         }],
       ],
     }],
-    [ 'branding == "Chrome"', {
-      'variables': {
-         'branding_dir': '../app/theme/google_chrome',
-      },
-    }, { # else branding!="Chrome"
-      'variables': {
-         'branding_dir': '../app/theme/chromium',
-      },
-    }],
   ],
 }