function getTextureTypeForArrayType(gl, src) {
    if (isArrayBuffer(src)) {
      return typedArrays.getGLTypeForTypedArray(src);
    }
    return gl.UNSIGNED_BYTE;
  }
Gets the texture type for a given array type.
@param {WebGLRenderingContext} gl the WebGLRenderingContext
@return {number} the gl texture type