mash: Re-enable mash_browser_tests in ozone builder.

testing/buildbot/chromium.chromiumos.json

 {
   "Linux ChromiumOS Builder": {
     "additional_compile_targets": [
       "All"
     ]
   },
   "Linux ChromiumOS GN": {
     "additional_compile_targets": [
       "gn_all"
     ],
@@ skipping 93 matching lines @@
         },
         "test": "aura_unittests"
       },
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "base_unittests"
       },
       {
+        "args": [
+          "--override-use-gl-with-osmesa-for-tests",
+          "--run-in-mash",
+          "--test-launcher-filter-file=src/testing/buildbot/filters/mash.browser_tests.filter",
+          "--use-test-config"
+        ],
+        "name": "mash_browser_tests",
+        "swarming": {
+          "can_use_on_swarming_builders": false
+        },
+        "test": "browser_tests"
+      },
+      {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "cacheinvalidation_unittests"
       },
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "capture_unittests"
@@ skipping 963 matching lines @@
       },
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "wm_unittests"
       }
     ]
   }
 }