Policy: Add ProxyMode and deprecate ProxyServerMode.

tools/grit/grit/format/policy_templates/writers/reg_writer.py

Index: tools/grit/grit/format/policy_templates/writers/reg_writer.py
diff --git a/tools/grit/grit/format/policy_templates/writers/reg_writer.py b/tools/grit/grit/format/policy_templates/writers/reg_writer.py
index 5d03fbd8347756065176e55622305322e7b86837..4cf07cd40a9cf2fe4b83c9250809fa39a4adedf7 100644
--- a/tools/grit/grit/format/policy_templates/writers/reg_writer.py
+++ b/tools/grit/grit/format/policy_templates/writers/reg_writer.py
@@ -56,8 +56,10 @@ class RegWriter(template_writer.TemplateWriter):
           example_value_str = 'dword:1'
         else:
           example_value_str = 'dword:0'
-      elif policy['type'] == 'enum':
+      elif policy['type'] == 'int-enum':
         example_value_str = 'dword:%d' % example_value
+      elif policy['type'] == 'string-enum':
+        example_value_str = '"%s"' % example_value
       else:
         raise Exception('unknown policy type %s:' % policy['type'])