Delete the GTK+ port of Chrome.

content/browser/gpu/test_support_gpu.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.
 
 # This file is meant to be included into targets which run gpu tests.
 {
   'variables': {
      'test_list_out_dir': '<(SHARED_INTERMEDIATE_DIR)/content/test/gpu',
      'src_dir': '../../..',
   },
@@ skipping 33 matching lines @@
               'LinkIncremental': '<(msvs_large_module_debug_link_mode)',
             },
           },
         },
       },
     }],
     ['OS=="mac"', {
       # See comments about "xcode_settings" elsewhere in this file.
       'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-ObjC']},
     }],
-    ['toolkit_uses_gtk == 1', {
-       'dependencies': [
-         '<(src_dir)/build/linux/system.gyp:gtk',
-       ],
-    }],
     ['toolkit_uses_gtk == 1 or chromeos==1 or (OS=="linux" and use_aura==1)', {
       'dependencies': [
         '<(src_dir)/build/linux/system.gyp:ssl',
       ],
     }],
     ['toolkit_views==1', {
       'dependencies': [
        '<(src_dir)/ui/views/views.gyp:views',
       ],
     }],
   ],
 }