Bug 1481913 - Allow texture direct mapping by default on macOS. r=mstange

Differential Revision: https://phabricator.services.mozilla.com/D2960

--HG--
extra : moz-landing-system : lando

gfx/thebes/gfxPrefs.h

@@ -513,13 +513,7 @@ private:
   DECL_GFX_PREF(Once, "gfx.use-iosurface-textures",            UseIOSurfaceTextures, bool, false);
   DECL_GFX_PREF(Once, "gfx.use-mutex-on-present",              UseMutexOnPresent, bool, false);
   DECL_GFX_PREF(Once, "gfx.use-surfacetexture-textures",       UseSurfaceTextureTextures, bool, false);
-
-#if defined(RELEASE_OR_BETA)
-  DECL_GFX_PREF(Once, "gfx.allow-texture-direct-mapping",      AllowTextureDirectMapping, bool, false);
-#else
   DECL_GFX_PREF(Once, "gfx.allow-texture-direct-mapping",      AllowTextureDirectMapping, bool, true);
-#endif
-
   DECL_GFX_PREF(Live, "gfx.vsync.collect-scroll-transforms",   CollectScrollTransforms, bool, false);
   DECL_GFX_PREF(Once, "gfx.vsync.compositor.unobserve-count",  CompositorUnobserveCount, int32_t, 10);