Support nullable types in mojom.

mojo/public/tools/bindings/pylib/mojom/generate/data.py

 # Copyright 2013 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.
 
 # TODO(vtl): "data" is a pretty vague name. Rename it?
 
 import copy
 
 import module as mojom
 
@@ skipping 81 matching lines @@
       return result
   return value
 
 def KindToData(kind):
   return kind.spec
 
 def KindFromData(kinds, data, scope):
   kind = LookupKind(kinds, data, scope)
   if kind:
     return kind
-  if data.startswith('a:'):
+  if data.startswith('?'):
+    kind = mojom.Nullable()
+    kind.SetKind(KindFromData(kinds, data[1:], scope))
+  elif data.startswith('a:'):
     kind = mojom.Array()
     kind.kind = KindFromData(kinds, data[2:], scope)
   elif data.startswith('r:'):
     kind = mojom.InterfaceRequest()
     kind.kind = KindFromData(kinds, data[2:], scope)
   elif data.startswith('a'):
     colon = data.find(':')
     length = int(data[1:colon])
     kind = mojom.FixedArray(length)
     kind.kind = KindFromData(kinds, data[colon+1:], scope)
@@ skipping 238 matching lines @@
 def OrderedModuleFromData(data):
   module = ModuleFromData(data)
   next_interface_ordinal = 0
   for interface in module.interfaces:
     next_ordinal = 0
     for method in interface.methods:
       if method.ordinal is None:
         method.ordinal = next_ordinal
       next_ordinal = method.ordinal + 1
   return module