Adds PrintingContext implementation stub for Android.

printing/printing.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 210 matching lines @@
           'sources': [
             'backend/print_backend_chromeos.cc',
           ],
         }],
         ['toolkit_uses_gtk==1 and chromeos==0', {
           'sources': [
             'printing_context_gtk.cc',
             'printing_context_gtk.h',
           ],
         }],
+        ['OS=="android"', {
+          'sources': [
+            'printing_context_android.h',

[Lei Zhang, 2013/08/13 23:26:37]

No printing_context_android.cc? How does that work?

[whywhat, 2013/08/13 23:38:48]

We figured that printing will not be compiled for Android without the private
repo (e.g. TestShell doesn't use printing). So we have a header in the public
repo but the .cc file is in the private repo. This is already used for
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/ui/...
for example.

Otherwise we'd have to provide a dummy implementation and some run-time hook
(like with MediaPlayerManager,
https://code.google.com/p/chromium/codesearch#chromium/src/media/base/android...)
to override the dummy implementation if the private repo is present.

Unfortunately, GYP can't replace .cc file based on whether we have the private
repo or not AFAIK.

+          ],
+        }],
       ],
     },
     {
       'target_name': 'printing_unittests',
       'type': 'executable',
       'dependencies': [
         'printing',
         '../testing/gtest.gyp:gtest',
         '../base/base.gyp:test_support_base',
         '../ui/ui.gyp:ui',
@@ skipping 79 matching lines @@
                   '<!@(python cups_config_helper.py --cflags)',
                 ],
               }],
             ],
           },
         }],
       ],
     },
   ],
 }