Remove lib/dom directory!

lib/dom/templates/html/dart2js/impl_MouseEvent.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.
-
-class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
-$!MEMBERS
-
-  int get offsetX() {
-    if (JS('bool', '!!this.offsetX')) {
-      return this._offsetX;
-    } else {
-      // Firefox does not support offsetX.
-      var target = this.target;
-      if (!(target is Element)) {
-        throw const UnsupportedOperationException(
-            'offsetX is only supported on elements');
-      }
-      return this.clientX - this.target.$dom_getBoundingClientRect().left;
-    }
-  }
-
-  int get offsetY() {
-    if (JS('bool', '!!this.offsetY')) {
-      return this._offsetY;
-    } else {
-      // Firefox does not support offsetY.
-      var target = this.target;
-      if (!(target is Element)) {
-        throw const UnsupportedOperationException(
-            'offsetX is only supported on elements');
-      }
-      return this.clientY - this.target.$dom_getBoundingClientRect().top;
-    }
-  }
-
-  int get _offsetX() native 'return this.offsetX';
-  int get _offsetY() native 'return this.offsetY';
-}