Removed DARTIUM codegen for IDLS (sdk/lib/dartium)

tools/dom/templates/html/dartium/impl_KeyboardEvent.darttemplate

-// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-part of $LIBRARYNAME;
-
-
-$(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
-
-  factory $CLASSNAME(String type, {
-      Window view,
-      bool canBubble: true,
-      bool cancelable: true,
-      int location,
-      int keyLocation, // Legacy alias for location
-      bool ctrlKey: false,
-      bool altKey: false,
-      bool shiftKey: false,
-      bool metaKey: false}) {
-    if (view == null) {
-      view = window;
-    }
-    location ??= keyLocation ?? 1;
-    final e = document._createEvent("KeyboardEvent");
-    e._initKeyboardEvent(type, canBubble, cancelable, view, "",
-        location, ctrlKey, altKey, shiftKey, metaKey);
-    return e;
-  }
-
-  @DomName('KeyboardEvent.keyCode')
-  int get keyCode => _keyCode;
-
-  @DomName('KeyboardEvent.charCode')
-  int get charCode => _charCode;
-
-  @DomName('KeyboardEvent.which')
-  int get which => _which;
-$!MEMBERS
-}