Mojo: Add support for constants to the IDL compiler.

mojo/public/tools/bindings/pylib/mojom/parse/lexer.py

 # Copyright 2014 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.
 
 import imp
 import os.path
 import sys
 
 # Disable lint check for finding modules:
 # pylint: disable=F0401
@@ skipping 49 matching lines @@
     'DATA_PIPE_CONSUMER',
     'DATA_PIPE_PRODUCER',
     'MESSAGE_PIPE',
     'SHARED_BUFFER',
 
     'IMPORT',
     'MODULE',
     'STRUCT',
     'INTERFACE',
     'ENUM',
+    'CONST',
   )
 
   keyword_map = {}
   for keyword in keywords:
     keyword_map[keyword.lower()] = keyword
 
   ##
   ## All the tokens recognized by the lexer
   ##
   tokens = keywords + (
@@ skipping 203 matching lines @@
     return t
 
   # Ignore C and C++ style comments
   def t_COMMENT(self, t):
     r'(/\*(.|\n)*?\*/)|(//.*(\n[ \t]*//.*)*)'
     pass
 
   def t_error(self, t):
     msg = 'Illegal character %s' % repr(t.value[0])
     self._error(msg, t)