mojom: Add associative arrays to the mojom language.

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

Index: mojo/public/tools/bindings/pylib/mojom/parse/parser.py
diff --git a/mojo/public/tools/bindings/pylib/mojom/parse/parser.py b/mojo/public/tools/bindings/pylib/mojom/parse/parser.py
index 551c04909aaed7c067bf0323e010f1ad3adbbae2..7d668f153a954983a7e10f057fead29973e0a805 100644
--- a/mojo/public/tools/bindings/pylib/mojom/parse/parser.py
+++ b/mojo/public/tools/bindings/pylib/mojom/parse/parser.py
@@ -237,6 +237,7 @@ class Parser(object):
     """nonnullable_typename : basictypename
                             | array
                             | fixed_array
+                            | associative_array
                             | interfacerequest"""
     p[0] = p[1]
 
@@ -275,6 +276,10 @@ class Parser(object):
                        snippet=self._GetSnippet(p.lineno(5)))
     p[0] = p[3] + "[" + p[5] + "]"
 
+  def p_associative_array(self, p):
+    """associative_array : MAP LANGLE identifier COMMA typename RANGLE"""
+    p[0] = p[5] + "{" + p[3] + "}"
+
   def p_interfacerequest(self, p):
     """interfacerequest : identifier AMP"""
     p[0] = p[1] + "&"