docstrings added.

theano/compile/profiling.py

@@ -295,6 +295,8 @@ class ProfileStats(object):
         return rval
 
     def fill_node_total_time(self, node, total_times):
+        """node -> fill total time icluding its parents (returns nothing)"""
+        # timing is stored by node, we compute total time on demand
         total = self.apply_time[node]
         for parent in node.get_parents():
             if parent.owner in self.apply_time.keys():
@@ -304,6 +306,7 @@ class ProfileStats(object):
         total_times[node] = total
 
     def compute_total_times(self):
+        """dict op -> total time icluding the time for parents"""
         rval = {}
         for node in self.apply_time.keys():
             if node not in rval: