Disable WebGL Multisampling on Chromecast Mali.

Bug: 831781
Test: run webgl pages, observe no corruption
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Change-Id: I6094d6b4ba5e8b026646197600d30b44ab1ff132
Reviewed-on: https://chromium-review.googlesource.com/1010474Reviewed-by: Kenneth Russell <kbr@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Commit-Queue: Alex Sakhartchouk <alexst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#550365}

gpu/config/gpu_driver_bug_list.json

@@ -2897,6 +2897,22 @@
         "GL_EXT_disjoint_timer_query",
         "GL_EXT_disjoint_timer_query_webgl2"
       ]
+    },
+    {
+      "id": 267,
+      "cr_bugs": [831781],
+      "description": "WebGL with multisampling produces errors on Mali",
+      "os": {
+        "type": "linux"
+      },
+      "gl_vendor": "ARM",
+      "gl_renderer": "Mali-TDVX",
+      "disabled_extensions": [
+        "GL_EXT_multisampled_render_to_texture"
+      ],
+      "features": [
+        "disable_chromium_framebuffer_multisample"
+      ]
     }
   ]
 }