Added tests to previously broken functionality and added null checks.

sdk/lib/web_gl/dart2js/web_gl_dart2js.dart

 library dart.dom.web_gl;
 
 import 'dart:collection';
 import 'dart:_collection-dev';
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:typed_data';
 import 'dart:_js_helper' show Creates, JSName, Null, Returns, convertDartClosureToJS;
 import 'dart:_foreign_helper' show JS;
 import 'dart:_interceptors' show Interceptor;
@@ skipping 2384 matching lines @@
   @DocsEditable
   void stencilOp(int fail, int zfail, int zpass) native;
 
   @DomName('WebGLRenderingContext.stencilOpSeparate')
   @DocsEditable
   void stencilOpSeparate(int face, int fail, int zfail, int zpass) native;
 
   @DomName('WebGLRenderingContext.texImage2D')
   @DocsEditable
   void texImage2D(int target, int level, int internalformat, int format_OR_width, int height_OR_type, border_OR_canvas_OR_image_OR_pixels_OR_video, [int format, int type, TypedData pixels]) {
-    if ((border_OR_canvas_OR_image_OR_pixels_OR_video is int || border_OR_canvas_OR_image_OR_pixels_OR_video == null)) {
+    if ((border_OR_canvas_OR_image_OR_pixels_OR_video is int || border_OR_canvas_OR_image_OR_pixels_OR_video == null) && format != null && type != null) {
       _texImage2D_1(target, level, internalformat, format_OR_width, height_OR_type, border_OR_canvas_OR_image_OR_pixels_OR_video, format, type, pixels);
       return;
     }
     if ((border_OR_canvas_OR_image_OR_pixels_OR_video is ImageData || border_OR_canvas_OR_image_OR_pixels_OR_video == null) && !?format && !?type && !?pixels) {
       var pixels_1 = _convertDartToNative_ImageData(border_OR_canvas_OR_image_OR_pixels_OR_video);
       _texImage2D_2(target, level, internalformat, format_OR_width, height_OR_type, pixels_1);
       return;
     }
     if ((border_OR_canvas_OR_image_OR_pixels_OR_video is ImageElement || border_OR_canvas_OR_image_OR_pixels_OR_video == null) && !?format && !?type && !?pixels) {
       _texImage2D_3(target, level, internalformat, format_OR_width, height_OR_type, border_OR_canvas_OR_image_OR_pixels_OR_video);
@@ skipping 34 matching lines @@
   @DocsEditable
   void texParameterf(int target, int pname, num param) native;
 
   @DomName('WebGLRenderingContext.texParameteri')
   @DocsEditable
   void texParameteri(int target, int pname, int param) native;
 
   @DomName('WebGLRenderingContext.texSubImage2D')
   @DocsEditable
   void texSubImage2D(int target, int level, int xoffset, int yoffset, int format_OR_width, int height_OR_type, canvas_OR_format_OR_image_OR_pixels_OR_video, [int type, TypedData pixels]) {
-    if ((canvas_OR_format_OR_image_OR_pixels_OR_video is int || canvas_OR_format_OR_image_OR_pixels_OR_video == null)) {
+    if ((canvas_OR_format_OR_image_OR_pixels_OR_video is int || canvas_OR_format_OR_image_OR_pixels_OR_video == null) && type != null) {
       _texSubImage2D_1(target, level, xoffset, yoffset, format_OR_width, height_OR_type, canvas_OR_format_OR_image_OR_pixels_OR_video, type, pixels);
       return;
     }
     if ((canvas_OR_format_OR_image_OR_pixels_OR_video is ImageData || canvas_OR_format_OR_image_OR_pixels_OR_video == null) && !?type && !?pixels) {
       var pixels_1 = _convertDartToNative_ImageData(canvas_OR_format_OR_image_OR_pixels_OR_video);
       _texSubImage2D_2(target, level, xoffset, yoffset, format_OR_width, height_OR_type, pixels_1);
       return;
     }
     if ((canvas_OR_format_OR_image_OR_pixels_OR_video is ImageElement || canvas_OR_format_OR_image_OR_pixels_OR_video == null) && !?type && !?pixels) {
       _texSubImage2D_3(target, level, xoffset, yoffset, format_OR_width, height_OR_type, canvas_OR_format_OR_image_OR_pixels_OR_video);
@@ skipping 204 matching lines @@
 }
 // 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('WebGLVertexArrayObjectOES')
 class VertexArrayObject native "WebGLVertexArrayObjectOES" {
 }