枚举成员

ANGLE_instanced_arrays: 1
EXT_color_buffer_float: 11
EXT_color_buffer_half_float: 7
EXT_shader_texture_lod: 8
EXT_sRGB: 10
EXT_texture_filter_anisotropic: 12
OES_element_index_uint: 5
OES_standard_derivatives: 19
OES_texture_float: 4
OES_texture_float_linear: 6
OES_texture_half_float: 2
OES_texture_half_float_linear: 3
OES_vertex_array_object: 0
WEBGL_compressed_texture_astc: 18
WEBGL_compressed_texture_etc: 17
WEBGL_compressed_texture_etc1: 16
WEBGL_compressed_texture_pvrtc: 15
WEBGL_compressed_texture_s3tc: 13
WEBGL_compressed_texture_s3tc_srgb: 14
WEBGL_depth_texture: 9