Fix various warnings and errors in html_diff and its annotations.

client/html/htmlimpl.dart

 // Copyright (c) 2011, 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.
 
 // DO NOT EDIT
 // Auto-generated Dart HTML library.
 
 #library('htmlimpl');
 
 #import('dart:dom', prefix:'dom');
@@ skipping 142 matching lines @@
 #source('generated/src/wrapping/_Int16ArrayWrappingImplementation.dart');
 #source('generated/src/wrapping/_Int32ArrayWrappingImplementation.dart');
 #source('generated/src/wrapping/_Int8ArrayWrappingImplementation.dart');
 #source('generated/src/wrapping/_JavaScriptAudioNodeWrappingImplementation.dart');
 #source('generated/src/wrapping/_KeygenElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_LIElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_LabelElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_LegendElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_LinkElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_LocationWrappingImplementation.dart');
-#source('generated/src/wrapping/_LoseContextWrappingImplementation.dart');
 #source('generated/src/wrapping/_LowPass2FilterNodeWrappingImplementation.dart');
 #source('generated/src/wrapping/_MapElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_MarqueeElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_MediaElementAudioSourceNodeWrappingImplementation.dart');
 #source('generated/src/wrapping/_MediaElementWrappingImplementation.dart');
 #source('generated/src/wrapping/_MediaErrorWrappingImplementation.dart');
 #source('generated/src/wrapping/_MediaListWrappingImplementation.dart');
 #source('generated/src/wrapping/_MediaQueryListListenerWrappingImplementation.dart');
 #source('generated/src/wrapping/_MediaQueryListWrappingImplementation.dart');
 #source('generated/src/wrapping/_MenuElementWrappingImplementation.dart');
@@ skipping 258 matching lines @@
 #source('src/DocumentWrappingImplementation.dart');
 #source('src/DOMApplicationCacheWrappingImplementation.dart');
 #source('src/DOMWrapperBase.dart');
 #source('src/ElementWrappingImplementation.dart');
 #source('src/ErrorEventWrappingImplementation.dart');
 #source('src/EventSourceWrappingImplementation.dart');
 #source('src/EventTargetWrappingImplementation.dart');
 #source('src/EventWrappingImplementation.dart');
 #source('src/HashChangeEventWrappingImplementation.dart');
 #source('src/KeyboardEventWrappingImplementation.dart');
+#source('src/LoseContextWrappingImplementation.dart');
 #source('src/Measurement.dart');
 #source('src/MessageEventWrappingImplementation.dart');
 #source('src/MessagePortWrappingImplementation.dart');
 #source('src/MouseEventWrappingImplementation.dart');
 #source('src/MutationEventWrappingImplementation.dart');
 #source('src/NodeWrappingImplementation.dart');
 #source('src/NotificationWrappingImplementation.dart');
 #source('src/ObjectElementWrappingImplementation.dart');
 #source('src/OverflowEventWrappingImplementation.dart');
 #source('src/PageTransitionEventWrappingImplementation.dart');
@@ skipping 10 matching lines @@
 #source('src/TouchEventWrappingImplementation.dart');
 #source('src/TransitionEventWrappingImplementation.dart');
 #source('src/UIEventWrappingImplementation.dart');
 #source('src/WebSocketWrappingImplementation.dart');
 #source('src/WheelEventWrappingImplementation.dart');
 #source('src/WindowWrappingImplementation.dart');
 #source('src/WorkerWrappingImplementation.dart');
 #source('src/XMLHttpRequestProgressEventWrappingImplementation.dart');
 #source('src/XMLHttpRequestUploadWrappingImplementation.dart');
 #source('src/XMLHttpRequestWrappingImplementation.dart');