Get a minimal unit_tests target building and running for iOS

chrome/common_constants.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,
   },
 
   'includes': [
@@ skipping 47 matching lines @@
     {
       'target_name': 'common_constants',
       'type': 'static_library',
       'include_dirs': [
         '<(SHARED_INTERMEDIATE_DIR)',  # Needed by chrome_paths.cc.
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../third_party/widevine/cdm/widevine_cdm.gyp:widevine_cdm_version_h',
       ],
+      'target_conditions': [
+        ['OS=="ios"', {
+          # iOS needs chrome_paths_mac, which is excluded by filename rules;
+          # re-add it in target_conditionals so it's after that exclusion.

[Nico, 2012/11/15 18:01:33]

Is there a file name rule for files that are used on both mac and ios?

It's a bit confusing that _mac.mm is excluded on iOS, but OS_MACOSX is
apparently true on iOS.

[stuartmorgan, 2012/11/15 18:23:11]

No. I spoke to Mark about this quite a while ago, and suggested _apple, but he
was strongly opposed and wanted us to just include specific _mac files.
Agreed, but our feeling is that the alternative is worse. There's a whole lot of
_mac and /mac/ files that we don't want, and re-excluding them would be more
painful that doing targeted includes. OS_MACOSX and OS_IOS follows the Apple
convention used for availability macro headers, where OS X is always true, even
on iOS. And within files we do use, MACOSX is often the right thing for us,
since there is a lot of shared code in Foundation and such.

I can try to get numbers on both the ifdef and the files if you want, and we can
re-open the discussion. I really don't think we should make our macros work
differently than the exactly corresponding Apple macros though.

[Nico, 2012/11/15 18:27:22]

It's ok, I was just curious.

+          'sources/': [
+            ['include', '^common/chrome_paths_mac\\.mm$'],
+          ],
+        }],
+      ],
       'conditions': [
         ['toolkit_uses_gtk == 1', {
           'dependencies': ['../build/linux/system.gyp:gtk'],
         }],
       ],
     },
   ],
   'conditions': [
     ['OS=="win"', {
       'targets': [
@@ skipping 14 matching lines @@
           'configurations': {
             'Common_Base': {
               'msvs_target_platform': 'x64',
             },
           },
         },
       ],
     }],
   ],
 }