gl.getSupportedExtensions return empty.

[Molay]

webgl_rendering_context.cc

napi_value WebGLRenderingContext::GetSupportedExtensions(...
std::string s(context->eglContextWrapper_->angle_requestable_extensions
                    ->GetExtensions());

the s value is empty.

printf("angle_requestable_extensions: %s\n\n", context->eglContextWrapper_->angle_requestable_extensions
                    ->GetExtensions());
printf("egl_extensions: %s\n\n", context->eglContextWrapper_->egl_extensions
                    ->GetExtensions());
printf("gl_extensions: %s\n\n", context->eglContextWrapper_->gl_extensions
                    ->GetExtensions());

output:

angle_requestable_extensions: 

egl_extensions: EGL_KHR_create_context EGL_KHR_get_all_proc_addresses EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_iosurface_client_buffer EGL_ANGLE_create_context_extensions_enabled EGL_ANDROID_blob_cache EGL_ANDROID_recordable 

gl_extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_memory_size GL_ANGLE_multi_draw GL_ANGLE_program_cache_control GL_ANGLE_provoking_vertex GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_multisample GL_ANGLE_texture_rectangle GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_texture GL_CHROMIUM_sync_query GL_EXT_blend_minmax GL_EXT_color_buffer_float GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_float_blend GL_EXT_frag_depth GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_multisample_compatibility GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_sRGB GL_EXT_sRGB_write_control GL_EXT_shader_texture_lod GL_EXT_texture_compression_dxt1 GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_parallel_shader_compile GL_NV_fence GL_NV_pack_subimage GL_OES_depth32 GL_OES_element_index_uint GL_OES_fbo_render_mipmap GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object