Add a Linux bot to run servicification related tests.

testing/buildbot/chromium.fyi.json

 {
   "Android Asan Builder Tests (dbg)": {
     "gtest_tests": [
       {
         "args": [
           "--tool=asan"
         ],
         "swarming": {
           "can_use_on_swarming_builders": false
         },
@@ skipping 11765 matching lines @@
           "--test-launcher-filter-file=../../testing/buildbot/filters/mojo.fyi.mus.browser_tests.filter"
         ],
         "hard_timeout": 60,
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "mus_browser_tests"
       }
     ]
   },
+  "Mojo Linux": {
+    "gtest_tests": [
+      {
+        "args": [
+          "--enable-network-service",
+          "--test-launcher-filter-file=../../testing/buildbot/filters/mojo.fyi.network_content_browsertests.filter"
+        ],
+        "name": "network_service_content_browsertests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "content_browsertests"
+      }
+    ]
+  },
   "Mojo Windows": {
     "additional_compile_targets": [
       "mash:all"
     ],
     "gtest_tests": [
       {
         "swarming": {
           "can_use_on_swarming_builders": false
         },
         "test": "media_service_unittests"
@@ skipping 1376 matching lines @@
       },
       {
         "swarming": {
           "can_use_on_swarming_builders": false
         },
         "test": "views_unittests"
       }
     ]
   }
 }