Use icu_gyp_path variable to reference ICU gyp file

samples/samples.gyp

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 24 matching lines @@
     'type': 'executable',
     'dependencies': [
       '../tools/gyp/v8.gyp:v8',
     ],
     'include_dirs': [
       '../include',
     ],
     'conditions': [
       ['v8_enable_i18n_support==1', {
         'dependencies': [
-          '<(DEPTH)/third_party/icu/icu.gyp:icui18n',
-          '<(DEPTH)/third_party/icu/icu.gyp:icuuc',
+          '<(icu_gyp_path):icui18n',
+          '<(icu_gyp_path):icuuc',
         ],
       }],
       ['OS=="win" and v8_enable_i18n_support==1', {
         'dependencies': [
-          '<(DEPTH)/third_party/icu/icu.gyp:icudata',
+          '<(icu_gyp_path):icudata',
         ],
       }],
     ],
   },
   'targets': [
     {
       'target_name': 'shell',
       'sources': [
         'shell.cc',
       ],
     },
     {
       'target_name': 'process',
       'sources': [
         'process.cc',
       ],
     },
     {
       'target_name': 'lineprocessor',
       'sources': [
         'lineprocessor.cc',
       ],
     }
   ],
 }