Fix pkgconfig wrapper for 64 bits

third_party/libpng/libpng.gyp

 # Copyright (c) 2011 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" and OS != "android"', {
         # Maybe link to system .so once the security concerns are thought
         # through, since we already use it due to GTK.
@@ skipping 72 matching lines @@
             ['OS=="android"', {
               'toolsets': ['target', 'host'],
             }],
           ],
         },
       ]
     }, {
       'conditions': [
         ['sysroot!=""', {
           'variables': {
-            'pkg-config': '../../build/linux/pkg-config-wrapper "<(sysroot)"',
+            'pkg-config': '../../build/linux/pkg-config-wrapper "<(sysroot)" "<(target_arch)"',
           },
         }, {
           'variables': {
             'pkg-config': 'pkg-config'
           },
         }],
       ],
       'targets': [
         {
           'target_name': 'libpng',
@@ skipping 15 matching lines @@
             ],
             'libraries': [
               '<!@(<(pkg-config) --libs-only-l libpng)',
             ],
           },
         },
       ],
     }],
   ],
 }