a few small refactorings to closure workarounds

lib/runtime/dart/web_gl.js

 dart_library.library('dart/web_gl', null, /* Imports */[
   'dart/_runtime',
-  'dart/_interceptors',
   'dart/core',
   'dart/html_common',
   'dart/html',
+  'dart/_interceptors',
   'dart/typed_data',
   'dart/_metadata',
   'dart/_js_helper'
 ], /* Lazy imports */[
-], function(exports, dart, _interceptors, core, html_common, html, typed_data, _metadata, _js_helper) {
+], function(exports, dart, core, html_common, html, _interceptors, typed_data, _metadata, _js_helper) {
   'use strict';
   let dartx = dart.dartx;
   const _getContextAttributes_1 = Symbol('_getContextAttributes_1');
   const _texImage2D_1 = Symbol('_texImage2D_1');
   const _texImage2D_2 = Symbol('_texImage2D_2');
   const _texImage2D_3 = Symbol('_texImage2D_3');
   const _texImage2D_4 = Symbol('_texImage2D_4');
   const _texImage2D_5 = Symbol('_texImage2D_5');
   const _texImage2DImageData_1 = Symbol('_texImage2DImageData_1');
   const _texSubImage2D_1 = Symbol('_texSubImage2D_1');
@@ skipping 2365 matching lines @@
   exports.OesTextureHalfFloatLinear = OesTextureHalfFloatLinear;
   exports.OesVertexArrayObject = OesVertexArrayObject;
   exports.Program = Program;
   exports.Renderbuffer = Renderbuffer;
   exports.Shader = Shader;
   exports.ShaderPrecisionFormat = ShaderPrecisionFormat;
   exports.Texture = Texture;
   exports.UniformLocation = UniformLocation;
   exports.VertexArrayObject = VertexArrayObject;
 });