Disable MESA_framebuffer_flip_y extension

The extension is not WebGL 2.0 compliant yet.

BUG=964010

Change-Id: I7c89e79d534ad16baba64215e9827558084d2423
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1620085
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Fritz Koenig <frkoenig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#661487}
diff --git a/gpu/config/gpu_driver_bug_list.json b/gpu/config/gpu_driver_bug_list.json
index f743656..ae077ab 100644
--- a/gpu/config/gpu_driver_bug_list.json
+++ b/gpu/config/gpu_driver_bug_list.json
@@ -3274,6 +3274,14 @@
       "features": [
         "disable_direct_composition_layers"
       ]
+    },
+    {
+      "id": 305,
+      "description": "Disable MESA_framebuffer_flip_y until passing WebGL 2.0 Conformance tests",
+      "cr_bugs": [964010],
+      "disabled_extensions": [
+        "GL_MESA_framebuffer_flip_y"
+      ]
     }
   ]
 }