Count document.createEvent() usage

third_party/WebKit/Source/build/scripts/make_event_factory.py

 #!/usr/bin/env python
 # Copyright (C) 2013 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 41 matching lines @@
             or name == 'Event'
             or name == 'Events'
             or name.startswith('UIEvent')
             or name.startswith('CustomEvent')
             or name == 'KeyboardEvent'
             or name == 'MessageEvent'
             or name.startswith('MouseEvent')
             or name == 'TouchEvent')
 
 
+# All events _not_ on the following whitelist are being measured in

[philipj_slow, 2016/02/11 14:40:28]

I like this approach! But can you reduce the list to just what the spec says? I
think there's some hope that device motion and orientation events could be
excluded from this list, and it would be a practical benefit if the list
eventually only contains things in core/.

(The things you remove should correspond to init*Event() with TODOs, but I may
not have documented all of them properly yet.

+# createEvent. The plan is to limit createEvent to just a few selected
+# events necessary for legacy content according to the specification:
+#
+# https://dom.spec.whatwg.org/#dom-document-createevent
+#
+# The criteria for the current whitelist, unless otherwise noted, is
+# to have a corresponding init*Event() function, or being an alias for
+# an event that has a corresponding init*Event(). It isn't a full
+# match with the spec yet.
+def candidate_whitelist(name):
+    return (name == 'CustomEvent'
+            or name == 'CompositionEvent'
+            or name == 'DeviceMotionEvent'
+            or name == 'DeviceOrientationEvent'
+            or name == 'Event'
+            or name == 'Events'
+            or name == 'HTMLEvents'
+            or name == 'KeyboardEvent'
+            or name == 'KeyboardEvents'
+            or name == 'MessageEvent'
+            or name == 'MouseEvent'
+            or name == 'MutationEvent'
+            or name == 'OrientationEvent'
+            or name == 'SVGEvents'
+            or name == 'SVGZoomEvent'  # Will be deprecated instead.
+            or name == 'StorageEvent'
+            or name == 'TextEvent'
+            or name == 'TouchEvent'
+            or name == 'UIEvent')
+
+
+def measure_name(name):
+    return 'DocumentCreateEvent' + name
+
 class EventFactoryWriter(in_generator.Writer):
     defaults = {
         'ImplementedAs': None,
         'RuntimeEnabled': None,
     }
     default_parameters = {
         'export': '',
         'namespace': '',
         'suffix': '',
     }
     filters = {
         'cpp_name': name_utilities.cpp_name,
         'lower_first': name_utilities.lower_first,
         'case_insensitive_matching': case_insensitive_matching,
         'script_name': name_utilities.script_name,
+        'candidate_whitelist': candidate_whitelist,
+        'measure_name': measure_name,
     }
 
     def __init__(self, in_file_path):
         super(EventFactoryWriter, self).__init__(in_file_path)
         self.namespace = self.in_file.parameters['namespace'].strip('"')
         self.suffix = self.in_file.parameters['suffix'].strip('"')
         self._validate_entries()
         self._outputs = {(self.namespace + self.suffix + "Headers.h"): self.generate_headers_header,
                          (self.namespace + self.suffix + ".cpp"): self.generate_implementation,
                         }
@@ skipping 60 matching lines @@
     def generate_implementation(self):
         return {
             'namespace': self.namespace,
             'suffix': self.suffix,
             'events': self.in_file.name_dictionaries,
         }
 
 
 if __name__ == "__main__":
     in_generator.Maker(EventFactoryWriter).main(sys.argv)