Support -Goutput_dir=blahblah in GN-GYP hybrid mode

gpu/gpu_config.gypi

 # 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.
 
 {
   'dependencies': [
+    '../<(gyp_output_dir)/gn_gyp/third_party/re2/re2.gyp:re2',
     '../base/base.gyp:base',
-    '../out/gn_gyp/third_party/re2/re2.gyp:re2',
     '../ui/gl/gl.gyp:gl',
   ],
   'include_dirs': [
     '..',
   ],
   'sources': [
     'config/dx_diag_node.cc',
     'config/dx_diag_node.h',
     'config/gpu_blacklist.cc',
     'config/gpu_blacklist.h',
@@ skipping 45 matching lines @@
       ],
     }],
     ['OS=="linux" and use_x11==1', {
       'dependencies': [
         '../build/linux/system.gyp:libpci',
         '../third_party/libXNVCtrl/libXNVCtrl.gyp:libXNVCtrl',
       ],
     }],
   ],
 }