Why extension list is different when running in WebGL inspector?

Here is the list of GL extensions I get when I run my WebGL project:

GL_WEBKIT_WEBGL_compressed_texture_s3tc
WEBKIT_EXT_texture_filter_anisotropic
OES_texture_float_linear
OES_texture_half_float_linear
GL_ANGLE_instanced_arrays
OES_vertex_array_object
WEBKIT_WEBGL_lose_context
WEBGL_debug_renderer_info
GL_WEBGL_lose_context
WEBGL_lose_context
GL_OES_texture_half_float
OES_standard_derivatives
GL_OES_texture_half_float_linear
OES_element_index_uint
OES_texture_float
GL_OES_texture_float_linear
GL_WEBGL_compressed_texture_s3tc
GL_OES_element_index_uint
GL_WEBGL_draw_buffers
ANGLE_instanced_arrays
EXT_texture_filter_anisotropic
GL_WEBKIT_EXT_texture_filter_anisotropic
GL_EXT_frag_depth
GL_OES_vertex_array_object
OES_texture_half_float
WEBGL_compressed_texture_s3tc
WEBGL_draw_buffers
GL_OES_standard_derivatives
WEBGL_depth_texture
EXT_frag_depth
GL_WEBGL_depth_texture
WEBKIT_WEBGL_compressed_texture_s3tc
GL_OES_texture_float
GL_WEBGL_debug_renderer_info
GL_EXT_texture_filter_anisotropic
GL_WEBKIT_WEBGL_depth_texture
GL_WEBKIT_WEBGL_lose_context
WEBKIT_WEBGL_depth_texture

And here is the list I get when I activate WebGL Inspector:

GL_WEBKIT_WEBGL_compressed_texture_s3tc
WEBKIT_EXT_texture_filter_anisotropic
GL_OES_texture_half_float
OES_standard_derivatives
OES_element_index_uint
OES_texture_float
GL_WEBGL_compressed_texture_s3tc
GL_OES_element_index_uint
EXT_texture_filter_anisotropic
GL_WEBKIT_EXT_texture_filter_anisotropic
OES_texture_half_float
WEBGL_compressed_texture_s3tc
GLI_frame_terminator
GL_GLI_frame_terminator
GL_OES_standard_derivatives
WEBKIT_WEBGL_compressed_texture_s3tc
GL_OES_texture_float
GL_EXT_texture_filter_anisotropic

Notice a lot are missing! Why is it different? Is this normal behavior??

This is annoying because my program actually make use of one of these extension, and somehow its not available when running in WebGL Inspector. How do I fix this?

Thanks!

Solution

Are you using WebGL inspector from the Chrome/Firefox AppStore ?

I remember having the same issue, turned out in older versions of WebGL-Inspector there was a whitelist blocking out all "unknown" extensions. The WebGL-Inspector project has been abandoned in favor of google web tracing framework: http://google.github.io/tracing-framework/

Thats why the Chrome/Firefox AppStore plugins are outdated, skimming through the old code on github it seems like the bug has been fixed. You may want to try to get the latest version from github and load it as an unpacked extension. https://github.com/benvanik/WebGL-Inspector

EDIT:

As brought to my attention the WebGL-Inspector is not abandoned, but it still features the whitelist approach.

For an introduction to WebGL debugging using Google Web Tracing Framework see: http://google.github.io/tracing-framework/analyzing-traces.html

Also note that there is experimental support for WebGL debugging in Chrome DevTools: http://www.html5rocks.com/en/tutorials/canvas/inspection/