Apply disable_post_sub_buffers_for_onscreen_surfaces only to mesa gl.

gpu/config/gpu_driver_bug_list_json.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Determines whether a certain driver bug exists in the current system.
 // The format of a valid gpu_driver_bug_list.json file is defined in
 // <gpu/config/gpu_control_list_format.txt>.
 // The supported "features" can be found in
 // <gpu/config/gpu_driver_bug_workaround_type.h>.
 
@@ skipping 761 matching lines @@
         "force_gl_finish_after_compositing"
       ]
     },
     {
       "id": 68,
       "description": "Disable partial swaps on linux drivers",
       "cr_bugs": [339493],
       "os": {
         "type": "linux"
       },
+      "driver_vendor": "Mesa",
       "features": [
         "disable_post_sub_buffers_for_onscreen_surfaces"
       ]
     },
     {
       "id": 69,
       "description": "Some shaders in Skia need more than the min available vertex and fragment shader uniform vectors in case of OSMesa",
       "cr_bugs": [174845],
       "driver_vendor": "osmesa",
       "features": [
@@ skipping 247 matching lines @@
       "features": [
         "etc1_power_of_two_only"
       ]
     }
   ]
 }
 
 );  // LONG_STRING_CONST macro
 
 }  // namespace gpu