Add dummy dart:html library for documentation.

lib/html/doc/interface/SpeechRecognitionError.dartdoc

+// 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.
+
+// WARNING:
+//   This file contains documentation that is merged into the real source.
+//   Do not make code changes here.
+
+/// @domName SpeechRecognitionError
+interface SpeechRecognitionError {
+
+  static final int ABORTED = 2;
+
+  static final int AUDIO_CAPTURE = 3;
+
+  static final int BAD_GRAMMAR = 7;
+
+  static final int LANGUAGE_NOT_SUPPORTED = 8;
+
+  static final int NETWORK = 4;
+
+  static final int NOT_ALLOWED = 5;
+
+  static final int NO_SPEECH = 1;
+
+  static final int OTHER = 0;
+
+  static final int SERVICE_NOT_ALLOWED = 6;
+
+  /** @domName SpeechRecognitionError.code */
+  final int code;
+
+  /** @domName SpeechRecognitionError.message */
+  final String message;
+}