Stub in Mac viewer code.

gyp/most.gyp

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 # Build ALMOST everything provided by Skia; this should be the default target.
 #
 # This omits the following targets that many developers won't want to build:
 # - debugger: this requires QT to build
 #
 {
@@ skipping 49 matching lines @@
         ['skia_os == "mac" or skia_os == "linux"', {
           'dependencies': [ 
             'nanomsg.gyp:*' ,
           ],
         }],
         ['skia_os in ["linux", "mac", "win"]', {
           'dependencies': [
             'skiaserve.gyp:skiaserve',
           ],
         }],
-        [ 'skia_os in ["win", "linux", "android"]', {
+        [ 'skia_os in ["win", "linux", "android", "mac"]', {
           'dependencies': [
             'viewer.gyp:viewer',
           ],
         }],
         [ 'skia_skip_gui',
           {
             'dependencies!': [
               'example.gyp:HelloWorld',
               'SampleApp.gyp:SampleApp',
             ]
           }
         ],
       ],
     },
   ],
 }