Fixing some warnings on Linux

gyp/libjpeg.gyp

 # Copyright 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.
 
 # This is a copy of ../third_party/externals/libjpeg/libjpeg.gyp , modified
 # such that all source paths point into that directory.
 # See http://code.google.com/p/skia/issues/detail?id=543 ('wrap libjpeg.gyp
 # from Chrome's libjpeg port, rather than making our own copy') for a better
 # long-term solution.
 
@@ skipping 75 matching lines @@
                '-Wno-main', # supresses warnings about naming things "main"
               ],
             }],
             ['OS=="android"', {
               'cflags!': [
                '-fno-rtti', # supresses warnings about invalid option of non-C++ code
                '-Wall',
                '-Werror',
               ],
             }],
+            ['OS in ["linux", "freebsd", "openbsd", "solaris", "nacl"]', {
+              'cflags!': [
+               '-Werror',
+              ],
+            }],
           ],
         },
       ],
     }, {
       'targets': [
         {
           'target_name': 'libjpeg',
           'type': 'none',
           'direct_dependent_settings': {
             'defines': [
               'USE_SYSTEM_LIBJPEG',
             ],
           },
           'link_settings': {
             'libraries': [
               '-ljpeg',
             ],
           },
         }
       ],
     }],
   ],
 }
 
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 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: