message: Fixes getTestContext to support Mesh in environments without WebGL
diff: import { settings } from '../../settings';
  import { ENV } from '@pixi/constants';
  -let context = null;
  +let context;
  /**
  * returns a little WebGL context to use for program inspection.
  @@ -12,7 +12,7 @@ let context = null;
  */
  export default function getTestContext()
  {
  - if (!context)
  + if (context !== undefined)
  {
  const canvas = document.createElement('canvas');
  @@ -31,7 +31,7 @@ export default function getTestContext()
  if (!gl)
  {
  // fail, not able to get a context
  - throw new Error('This browser does not support WebGL. Try using the canvas renderer');
  + gl = null;
  }
  else
  {
  @@ -41,8 +41,6 @@ export default function getTestContext()
  }
  context = gl;
  -
  - return gl;
  }
  return context;
  