fix --show-composited-layer-borders on Mac

gpu/command_buffer/build_gles2_cmd_buffer.py

 #!/usr/bin/env python
 # 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.
 
 """code generator for GLES2 command buffers."""
 
 import itertools
 import os
 import os.path
@@ skipping 2722 matching lines @@
     },
   },
   'Hint': {
     'type': 'StateSetNamedParameter',
     'state': 'Hint',
   },
   'CullFace': {'type': 'StateSet', 'state': 'CullFace'},
   'FrontFace': {'type': 'StateSet', 'state': 'FrontFace'},
   'DepthFunc': {'type': 'StateSet', 'state': 'DepthFunc'},
   'LineWidth': {
-    'type': 'StateSet',
+    'type': 'Custom',

[piman, 2016/11/07 19:38:01]

Rather than using "Custom" which completely removes the autogenerated code, can
you use a regular function (remove the 'type' attribute, leaving the
decoder_func), and move the logic (extra validation, state tracking) to the
DoLineWidth function?

     'state': 'LineWidth',
-    'decoder_func': 'DoLineWidth',
     'valid_args': {
       '0': '2.0f'
     },
   },
   'PolygonOffset': {
     'type': 'StateSet',
     'state': 'PolygonOffset',
   },
   'DeleteBuffers': {
     'type': 'DELn',
@@ skipping 8419 matching lines @@
   Format(gen.generated_cpp_filenames)
 
   if gen.errors > 0:
     print "%d errors" % gen.errors
     return 1
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main(sys.argv[1:]))