This makes the OpenGL entry points loaded at Adapter creation from the
getProcAddress passed in the DiscoveryOptions and update all GL calls in
the backend to go through the new OpenGLFunctions object.
A code generator is added that generates the function loader and list of
GL procs from Khronos' gl.xml file but we can't get rid of glad yet
because it is used to have the PROC typedefs and enum values.
BUG=dawn:165
Change-Id: I2a583d79752f55877fa4190846f5be16cf91651a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/7983
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Corentin Wallez