Fixing an issue where EXTDrawBuffers.drawBuffersEXT was not getting generated.

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 673 matching lines @@
   @DocsEditable
   static const int DRAW_BUFFER9_EXT = 0x882E;
 
   @DomName('EXTDrawBuffers.MAX_COLOR_ATTACHMENTS_EXT')
   @DocsEditable
   static const int MAX_COLOR_ATTACHMENTS_EXT = 0x8CDF;
 
   @DomName('EXTDrawBuffers.MAX_DRAW_BUFFERS_EXT')
   @DocsEditable
   static const int MAX_DRAW_BUFFERS_EXT = 0x8824;
+
+  @JSName('drawBuffersEXT')
+  @DomName('EXTDrawBuffers.drawBuffersEXT')
+  @DocsEditable
+  @Experimental // untriaged
+  void drawBuffersExt(List<int> buffers) 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('EXTFragDepth')
 // http://www.khronos.org/registry/webgl/extensions/EXT_frag_depth/
 @Experimental
@@ skipping 2118 matching lines @@
 
 
 @DocsEditable
 @DomName('WebGLVertexArrayObjectOES')
 // http://www.khronos.org/registry/webgl/extensions/OES_vertex_array_object/
 @Experimental // experimental
 class VertexArrayObject native "WebGLVertexArrayObjectOES" {
   // To suppress missing implicit constructor warnings.
   factory VertexArrayObject._() { throw new UnsupportedError("Not supported"); }
 }