806359 - Add non-default WebGL context creation attribs to display chrome message if user should update drivers

Status: NEW

(Core :: Graphics: CanvasWebGL, enhancement, P3)

Description

[Benoit Jacob [:bjacob] (mostly away)]

Add 2 new, false-by-default, boolean context creation attributes:

   warnOnContextCreationFailure
   warnOnNonOptimalWebGLExperience

(please suggest better names) whereby applications can opt in to get the browser warns the user when they're missing out and when they should try to update their drivers.

Reasons for this being opt-in:
 - don't want to break existing content that wants webgl creation failures to be silent.
 - this will be used even as opt-in: game developers are asking for something like that e.g. in bug 805434.

Reasons for this displaying a chrome message directly rather than exposing a content-facing API:
 - don't want to have to make compromises here between exposing useful information, and preserving privacy.
 - we've discussed content-facing solutions for 2 years now. Nothing really happened. It's tricky.