fix a todo from before the merge of shared variable into theano.

theano/compile/io.py

@@ -2,6 +2,7 @@
 __docformat__ = 'restructuredtext en'
 
 from theano import gof
+from sharedvalue import SharedVariable
 
 class SymbolicInput(object):
     """
@@ -175,12 +176,8 @@ class In(SymbolicInput):
             mutable=None, strict=False, autoname=True,
             implicit=None):
         if implicit is None:
-            # TODO Having a default value being a Variable only makes sense
-            # if this is a SharedVariable. This should be changed once shared
-            # variables are part of Theano instead of living in a separate
-            # repository.
             implicit = (isinstance(value, gof.Container) or
-                    isinstance(value, gof.Variable))
+                    isinstance(value, SharedVariable))
         super(In, self).__init__(variable, name, update, mutable, strict,
                 autoname, implicit = implicit)
         self.value = value