Reapply Futureification.

tools/dom/scripts/monitored.py

Index: tools/dom/scripts/monitored.py
diff --git a/tools/dom/scripts/monitored.py b/tools/dom/scripts/monitored.py
index e90330ae7c6ae66cfe2c727af35871efbfb1cd1f..06dc4dd2da9b5b0b3fd77919dedf4937336bf7ca 100644
--- a/tools/dom/scripts/monitored.py
+++ b/tools/dom/scripts/monitored.py
@@ -19,7 +19,7 @@ class MonitoredCollection(object):
     _monitored_values.append(self)
 
 class Dict(MonitoredCollection):
-  """Wrapper for a read-only dict that reports unused keys."""
+  """Wrapper for a dict that reports unused keys."""
 
   def __init__(self, name, map):
     super(Dict, self).__init__(name)
@@ -50,7 +50,7 @@ class Dict(MonitoredCollection):
 
 
 class Set(MonitoredCollection):
-  """Wrapper for a read-only set that reports unused keys."""
+  """Wrapper for a set that reports unused keys."""
 
   def __init__(self, name, a_set):
     super(Set, self).__init__(name)
@@ -60,6 +60,12 @@ class Set(MonitoredCollection):
     self._used_keys.add(key)
     return key in self._set
 
+  def __iter__(self):
+    return self._set.__iter__()
+
+  def add(self, key):
+    self._set += [key]
+
   def CheckUsage(self):
     for v in sorted(self._set):
       if v not in self._used_keys: