Support custom constructors with signature declaration.

lib/dom/scripts/fremontcutbuilder.py

Index: lib/dom/scripts/fremontcutbuilder.py
diff --git a/lib/dom/scripts/fremontcutbuilder.py b/lib/dom/scripts/fremontcutbuilder.py
index 07ae5b735b0a64b96267fded8440380b452395b0..635e6e6cd1ae35d0c23232a846e012e65118f63c 100755
--- a/lib/dom/scripts/fremontcutbuilder.py
+++ b/lib/dom/scripts/fremontcutbuilder.py
@@ -85,9 +85,6 @@ DEFAULT_FEATURE_DEFINES = [
     'ENABLE_XSLT',
 ]
 
-# TODO(antonm): Remove this filter.
-UNSUPPORTED_FEATURES = [ 'ENABLE_WEB_INTENTS' ]
-
 def build_database(idl_files, database_dir, feature_defines = None):
   """This code reconstructs the FremontCut IDL database from W3C,
   WebKit and Dart IDL files."""
@@ -113,8 +110,8 @@ def build_database(idl_files, database_dir, feature_defines = None):
 
   webkit_options = databasebuilder.DatabaseBuilderOptions(
       idl_syntax=idlparser.WEBKIT_SYNTAX,
-# TODO(vsm): What else should we define as on when processing IDL?
-      idl_defines=[define for define in webkit_defines + feature_defines if define not in UNSUPPORTED_FEATURES],
+      # TODO(vsm): What else should we define as on when processing IDL?
+      idl_defines=webkit_defines + feature_defines,
       source='WebKit',
       source_attributes={'revision': webkit_revision},
       type_rename_map={