Mojom: Add 'default' keyword for initializing structs to non-null value.

mojo/public/tools/bindings/pylib/mojom_tests/parse/lexer_unittest.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
 import unittest
 
 # Disable lint check for finding modules:
@@ skipping 59 matching lines @@
     self.assertEquals(self._SingleTokenForInput("import"),
                       _MakeLexTokenForKeyword("import"))
     self.assertEquals(self._SingleTokenForInput("module"),
                       _MakeLexTokenForKeyword("module"))
     self.assertEquals(self._SingleTokenForInput("struct"),
                       _MakeLexTokenForKeyword("struct"))
     self.assertEquals(self._SingleTokenForInput("interface"),
                       _MakeLexTokenForKeyword("interface"))
     self.assertEquals(self._SingleTokenForInput("enum"),
                       _MakeLexTokenForKeyword("enum"))
+    self.assertEquals(self._SingleTokenForInput("const"),
+                      _MakeLexTokenForKeyword("const"))
+    self.assertEquals(self._SingleTokenForInput("true"),
+                      _MakeLexTokenForKeyword("true"))
+    self.assertEquals(self._SingleTokenForInput("false"),
+                      _MakeLexTokenForKeyword("false"))
+    self.assertEquals(self._SingleTokenForInput("default"),
+                      _MakeLexTokenForKeyword("default"))
 
   def testValidIdentifiers(self):
     """Tests identifiers."""
     self.assertEquals(self._SingleTokenForInput("abcd"),
                       _MakeLexToken("NAME", "abcd"))
     self.assertEquals(self._SingleTokenForInput("AbC_d012_"),
                       _MakeLexToken("NAME", "AbC_d012_"))
     self.assertEquals(self._SingleTokenForInput("_0123"),
                       _MakeLexToken("NAME", "_0123"))
 
@@ skipping 80 matching lines @@
   def _SingleTokenForInput(self, input_string):
     """Gets the single token for the given input string. (Raises an exception if
     the input string does not result in exactly one token.)"""
     toks = self._TokensForInput(input_string)
     assert len(toks) == 1
     return toks[0]
 
 
 if __name__ == "__main__":
   unittest.main()