Initial support for cloudprint in print preview

printing/printing.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': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 129 matching lines @@
             # 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',
           ],
         }],
+        ['OS=="linux" and chromeos==1', {
+          'defines': [
+            # PRINT_BACKEND_AVAILABLE disables the default dummy implementation
+            # of the print backend and enables a custom implementation instead.
+            'PRINT_BACKEND_AVAILABLE',
+          ],
+          'sources': [
+            'backend/print_backend_chromeos.cc',
+          ],
+        }],
       ],
     },
     {
       'target_name': 'printing_unittests',
       'type': 'executable',
       'dependencies': [
         'printing',
         '../testing/gtest.gyp:gtest',
         '../base/base.gyp:test_support_base',
       ],
@@ skipping 56 matching lines @@
                   ],
                 },
               }],
             ],
           },
         }],
       ],
     },
   ],
 }