First pass at cleaning up html lib warnings from the analyzer.

sdk/lib/web_gl/dart2js/web_gl_dart2js.dart

 /**
  * 3D programming in the browser.
  */
 library dart.dom.web_gl;
 
 import 'dart:collection';
 import 'dart:_internal' hide deprecated;
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:_native_typed_data';
@@ skipping 3140 matching lines @@
    * Updates a sub-rectangle of the currently bound texture to [data].
    *
    * [data] can be either an [ImageElement], a
    * [CanvasElement], a [VideoElement], or an [ImageData] object.
    *
    * To use [texSubImage2d] with a TypedData object, use [texSubImage2dTyped].
    *
    */
   @JSName('texSubImage2D')
   void texSubImage2DUntyped(int targetTexture, int levelOfDetail,
-      int internalFormat, int format, int type, data) native;
+      int xOffset, int yOffset, int format, int type, data) native;
 
   /**
    * Updates a sub-rectangle of the currently bound texture to [data].
    */
   @JSName('texSubImage2D')
   void texSubImage2DTyped(int targetTexture, int levelOfDetail,
-      int internalFormat, int width, int height, int border, int format,
+      int xOffset, int yOffset, int width, int height, int border, int format,
       int type, TypedData data) native;
 }
 // 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.
 
 
 @DocsEditable()
 @DomName('WebGLShader')
 class Shader extends Interceptor native "WebGLShader" {
@@ skipping 51 matching lines @@
 
 
 @DocsEditable()
 @DomName('WebGLVertexArrayObjectOES')
 // http://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
 @Experimental() // experimental
 class VertexArrayObject extends Interceptor native "WebGLVertexArrayObjectOES" {
   // To suppress missing implicit constructor warnings.
   factory VertexArrayObject._() { throw new UnsupportedError("Not supported"); }
 }