Mac cloud print proxy work.

printing/printing.gyp

 # Copyright (c) 2010 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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 94 matching lines @@
             # of the print backend and enables a custom implementation instead.
             'PRINT_BACKEND_AVAILABLE',
           ],
           'sources': [
             'backend/win_helper.cc',
             'backend/win_helper.h',
             'backend/print_backend_win.cc',
           ],
         }],
         ['use_cups==1', {
-          'link_settings': {
-            'libraries': [
-              '-lcups',
-              '-lgcrypt',
-            ],
-          },
           'defines': [
             # PRINT_BACKEND_AVAILABLE disables the default dummy implementation
             # of the print backend and enables a custom implementation instead.
             'PRINT_BACKEND_AVAILABLE',
           ],
           'sources': [
             'backend/cups_helper.cc',
             'backend/cups_helper.h',
             'backend/print_backend_cups.cc',
           ],
+          'conditions': [
+            ['OS=="mac"', {
+              'link_settings': {
+                'libraries': [
+                  '$(SDKROOT)/usr/lib/libcups.dylib',
+                ]
+              },
+            }, {
+              'link_settings': {
+                'libraries': [
+                  '-lcups',
+                  '-lgcrypt',
+                ],
+              },
+            }],              
+          ],
         }],
       ],
     },
     {
       'target_name': 'printing_unittests',
       'type': 'executable',
       'msvs_guid': '8B2EE5D9-41BC-4AA2-A401-2DC143A05D2E',
       'dependencies': [
         'printing',
         '../testing/gtest.gyp:gtest',
@@ skipping 38 matching lines @@
       ],
     },
   ],
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: