src/twgl.js
function addExtensionsToContext(gl) {
  for (let ii = 0; ii < supportedExtensions.length; ++ii) {
    addExtensionToContext(gl, supportedExtensions[ii]);
  }
}
function addExtensionsToContext(gl) {
  for (let ii = 0; ii < supportedExtensions.length; ++ii) {
    addExtensionToContext(gl, supportedExtensions[ii]);
  }
}
function addExtensionsToContext ( gl ) { for ( let ii = 0 ; ii < supportedExtensions . length ; ++ ii ) { addExtensionToContext ( gl , supportedExtensions [ ii ] ) ; } }
Attempts to enable all of the following extensions
and add their functions and constants to the
`WebGLRenderingContext` using their normal non-extension like names.

ANGLE_instanced_arrays
EXT_blend_minmax
EXT_color_buffer_float
EXT_color_buffer_half_float
EXT_disjoint_timer_query
EXT_disjoint_timer_query_webgl2
EXT_frag_depth
EXT_sRGB
EXT_shader_texture_lod
EXT_texture_filter_anisotropic
OES_element_index_uint
OES_standard_derivatives
OES_texture_float
OES_texture_float_linear
OES_texture_half_float
OES_texture_half_float_linear
OES_vertex_array_object
WEBGL_color_buffer_float
WEBGL_compressed_texture_atc
WEBGL_compressed_texture_etc1
WEBGL_compressed_texture_pvrtc
WEBGL_compressed_texture_s3tc
WEBGL_compressed_texture_s3tc_srgb
WEBGL_depth_texture
WEBGL_draw_buffers

For example if `ANGLE_instanced_arrays` exists then the functions
`drawArraysInstanced`, `drawElementsInstanced`, `vertexAttribDivisor`
and the constant `VERTEX_ATTRIB_ARRAY_DIVISOR` are added to the
`WebGLRenderingContext`.

Note that if you want to know if the extension exists you should
probably call `gl.getExtension` for each extension. Alternatively
you can check for the existance of the functions or constants that
are expected to be added. For example

if (gl.drawBuffers) {
// Either WEBGL_draw_buffers was enabled OR you're running in WebGL2
....

@param {WebGLRenderingContext} gl A WebGLRenderingContext
@memberOf module:twgl
Attempts to enable all of the following extensions and add their functions and constants to the WebGLRenderingContext using their normal non - extension like names .