Spelling fixes e to i.

tools/dom/src/native_DOMImplementation.dart

 // 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 html;
 
 class _Property {
   _Property(this.name)
       : _hasValue = false,
         writable = false,
@@ skipping 502 matching lines @@
     }
 
     if (locals != null) {
       for (int i = 0; i < locals.length; i += 2) {
         addArg(locals[i], locals[i + 1]);
       }
     }
     // Inject all the already defined console variables.
     _consoleTempVariables._data.forEach(addArg);
 
-    // TODO(jacobr): remove the parentheses around the expresson once
+    // TODO(jacobr): remove the parentheses around the expression once
     // dartbug.com/13723 is fixed. Currently we wrap expression in parentheses
     // to ensure only valid Dart expressions are allowed. Otherwise the DartVM
     // quietly ignores trailing Dart statements resulting in user confusion
     // when part of an invalid expression they entered is ignored.
     sb..write(') => (\n$expression\n)');
     return [sb.toString(), args.values.toList(growable: false)];
   }
 
   static String _getShortSymbolName(
       Symbol symbol, DeclarationMirror declaration) {
@@ skipping 856 matching lines @@
 get _scheduleImmediateClosure => (void callback()) {
       _scheduleImmediateHelper._schedule(callback);
     };
 
 get _pureIsolateScheduleImmediateClosure => ((void callback()) =>
     throw new UnimplementedError("scheduleMicrotask in background isolates "
         "are not supported in the browser"));
 
 // Class for unsupported native browser 'DOM' objects.
 class _UnsupportedBrowserObject extends DartHtmlDomObject {}