Revert "Fix a few strong mode errors in dart:html"

tools/dom/scripts/htmleventgenerator.py

Index: tools/dom/scripts/htmleventgenerator.py
diff --git a/tools/dom/scripts/htmleventgenerator.py b/tools/dom/scripts/htmleventgenerator.py
index 9c1928a57652a4efdc4280b7bc53acdf075f8dc8..6e83fd3f1b829fb5bec95c2e5f96069548267395 100644
--- a/tools/dom/scripts/htmleventgenerator.py
+++ b/tools/dom/scripts/htmleventgenerator.py
@@ -123,7 +123,6 @@ _html_event_types = monitored.Dict('htmleventgenerator._html_event_types', {
   'ApplicationCache.obsolete': ('obsolete', 'Event'),
   'ApplicationCache.progress': ('progress', 'ProgressEvent'),
   'ApplicationCache.updateready': ('updateReady', 'Event'),
-  'CompositorWorker.error': ('error', 'ErrorEvent'),
   'Document.readystatechange': ('readyStateChange', 'Event'),
   'Document.securitypolicyviolation': ('securityPolicyViolation', 'SecurityPolicyViolationEvent'),
   'Document.selectionchange': ('selectionChange', 'Event'),
@@ -191,7 +190,6 @@ _html_event_types = monitored.Dict('htmleventgenerator._html_event_types', {
   'RTCPeerConnection.removestream': ('removeStream', 'MediaStreamEvent'),
   'RTCPeerConnection.signalingstatechange': ('signalingStateChange', 'Event'),
   'ScriptProcessorNode.audioprocess': ('audioProcess', 'AudioProcessingEvent'),
-  'SharedWorker.error': ('error', 'ErrorEvent'),
   'SharedWorkerGlobalScope.connect': ('connect', 'Event'),
   'SpeechRecognition.audioend': ('audioEnd', 'Event'),
   'SpeechRecognition.audiostart': ('audioStart', 'Event'),
@@ -223,7 +221,6 @@ _html_event_types = monitored.Dict('htmleventgenerator._html_event_types', {
   'Window.pageshow': ('pageShow', 'Event'),
   'Window.progress': ('progress', 'Event'),
   'Window.webkittransitionend': ('webkitTransitionEnd', 'TransitionEvent'),
-  'Worker.error': ('error', 'ErrorEvent'),
   'XMLHttpRequestEventTarget.abort': ('abort', 'ProgressEvent'),
   'XMLHttpRequestEventTarget.error': ('error', 'ProgressEvent'),
   'XMLHttpRequestEventTarget.load': ('load', 'ProgressEvent'),