Introduce new runtime feature state "deprecated" and use it for showModalDialog

Source/build/scripts/make_runtime_features.py

Index: Source/build/scripts/make_runtime_features.py
diff --git a/Source/build/scripts/make_runtime_features.py b/Source/build/scripts/make_runtime_features.py
index 0160b4ce3d5d3c09ce427b30fafcf65452917fb9..37fb09c891767590199bc2008707d1d4b7f8508a 100755
--- a/Source/build/scripts/make_runtime_features.py
+++ b/Source/build/scripts/make_runtime_features.py
@@ -43,7 +43,7 @@ class RuntimeFeatureWriter(in_generator.Writer):
 
     # FIXME: valid_values and defaults should probably roll into one object.
     valid_values = {
-        'status': ['stable', 'experimental', 'test'],
+        'status': ['stable', 'experimental', 'test', 'deprecated'],
     }
     defaults = {
         'condition' : None,
@@ -52,6 +52,10 @@ class RuntimeFeatureWriter(in_generator.Writer):
         'status': None,
     }
 
+    _status_aliases = {
+        'deprecated': 'test',
+    }
+
     def __init__(self, in_file_path):
         super(RuntimeFeatureWriter, self).__init__(in_file_path)
         self._outputs = {(self.class_name + '.h'): self.generate_header,
@@ -62,6 +66,7 @@ class RuntimeFeatureWriter(in_generator.Writer):
         # Make sure the resulting dictionaries have all the keys we expect.
         for feature in self._features:
             feature['first_lowered_name'] = lower_first(feature['name'])
+            feature['status'] = self._status_aliases.get(feature['status'], feature['status'])
             # Most features just check their isFooEnabled bool
             # but some depend on more than one bool.
             enabled_condition = 'is%sEnabled' % feature['name']
@@ -73,7 +78,7 @@ class RuntimeFeatureWriter(in_generator.Writer):
     def _feature_sets(self):
         # Another way to think of the status levels is as "sets of features"
         # which is how we're referring to them in this generator.
-        return self.valid_values['status']
+        return [status for status in self.valid_values['status'] if status not in self._status_aliases]
 
     @template_expander.use_jinja(class_name + '.h.tmpl', filters=filters)
     def generate_header(self):