Auto generate UseCounter::Feature enum from an .in file

Source/build/scripts/make_use_counter.py

+#!/usr/bin/env python
+
+# Copyright 2014 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.
+
+import media_feature_symbol
+import in_generator
+import template_expander
+import name_utilities
+import sys
+
+
+feature_count = 0
+
+
+def increment(value):
+    global feature_count
+    if (value):
+        feature_count = int(value)
+    else:
+        feature_count += 1
+    return feature_count
+
+
+class MakeUseCounterWriter(in_generator.Writer):
+    defaults = {
+        'value': None,
+    }
+    filters = {
+        'increment': increment,
+    }
+    default_parameters = {
+        'value': '',
+    }
+
+    def __init__(self, in_file_path):
+        super(MakeUseCounterWriter, self).__init__(in_file_path)
+
+        self._outputs = {
+            ('UseCounterGenerated.h'): self.generate_header,
+        }
+        self._template_context = {
+            'features': self.in_file.name_dictionaries,
+        }
+
+    @template_expander.use_jinja('UseCounterGenerated.h.tmpl', filters=filters)
+    def generate_header(self):
+        return self._template_context
+
+if __name__ == '__main__':
+    in_generator.Maker(MakeUseCounterWriter).main(sys.argv)