Extract an independent webkit_support_gfx target.

third_party/libpng/libpng.gyp

 # Copyright (c) 2009 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.
 
 {
   'variables': {
     'conditions': [
       [ 'os_posix == 1 and OS != "mac"', {
         # Link to system .so since we already use it due to GTK.
         'use_system_libpng%': 1,
@@ skipping 55 matching lines @@
               'defines': [
                 'PNG_BUILD_DLL',
                 'PNG_NO_MODULEDEF',
               ],
               'direct_dependent_settings': {
                 'defines': [
                   'PNG_USE_DLL',
                 ],
               },          
             }],
+            ['OS=="android"', {
+              'toolsets': ['target', 'host'],
+            }],
           ],
         },
       ]
     }, {
       'conditions': [
         ['sysroot!=""', {
           'variables': {
             'pkg-config': '../../build/linux/pkg-config-wrapper "<(sysroot)"',
           },
         }, {
@@ skipping 23 matching lines @@
             ],
             'libraries': [
               '<!@(<(pkg-config) --libs-only-l libpng)',
             ],
           },
         },
       ],
     }],
   ],
 }