Bug 1268638 - Enable DXGL by default. - r=jrmuizel

This will only run if they receive a WGL context, and we have a blocklist
entry for this. Since there isn't a reason right now to want WGL without
DXGL, we should tie these together.

MozReview-Commit-ID: ymtVT5dJIZ

modules/libpref/init/all.js

@@ -4429,7 +4429,7 @@ pref("webgl.vendor-string-override", "");
 pref("webgl.angle.try-d3d11", true);
 pref("webgl.angle.force-d3d11", false);
 pref("webgl.angle.force-warp", false);
-pref("webgl.dxgl.enabled", false);
+pref("webgl.dxgl.enabled", true);
 pref("webgl.dxgl.needs-finish", false);
 #endif