Revert "Revert "Refresh dart:dom""

client/dom/scripts/databasebuilder.py

Index: client/dom/scripts/databasebuilder.py
diff --git a/client/dom/scripts/databasebuilder.py b/client/dom/scripts/databasebuilder.py
index 5132ecbf5dcab9df65655b1be67f68abff8042c1..8da31476ecd9f5ba1d0c65351a97aaab7e7dcfc9 100755
--- a/client/dom/scripts/databasebuilder.py
+++ b/client/dom/scripts/databasebuilder.py
@@ -430,21 +430,25 @@ class DatabaseBuilder(object):
 
     # Step 2: Add all new interfaces and merge overlapping ones
     for interface, module_name, import_options in self._imported_interfaces:
-      if not self._database.HasInterface(interface.id):
-        if import_options.add_new_interfaces:
-          self._database.AddInterface(interface)
-      elif not interface.is_supplemental:
-        old_interface = self._database.GetInterface(interface.id)
-        self._merge_interfaces(old_interface, interface,
-          import_options)
+      if not interface.is_supplemental:
+        if self._database.HasInterface(interface.id):
+          old_interface = self._database.GetInterface(interface.id)
+          self._merge_interfaces(old_interface, interface, import_options)
+        else:
+          if import_options.add_new_interfaces:
+            self._database.AddInterface(interface)
 
     # Step 3: Merge in supplemental interfaces
     for interface, module_name, import_options in self._imported_interfaces:
-      if (interface.is_supplemental
-          and self._database.HasInterface(interface.id)):
-        old_interface = self._database.GetInterface(interface.id)
-        self._merge_interfaces(old_interface, interface,
-          import_options)
+      if interface.is_supplemental:
+        # For now, ignore WebKit [Supplemental=BaseInterface] attributes.
+        target = interface.ext_attrs['Supplemental']
+        if target:
+          continue
+        target = interface.id
+        if self._database.HasInterface(target):
+          old_interface = self._database.GetInterface(target)
+          self._merge_interfaces(old_interface, interface, import_options)
 
     # Step 4: Resolve 'implements' statements
     for impl_stmt, import_options in self._impl_stmts: