PlzNavigate: adds Linux runs of content_browsertests to the CQ.

testing/buildbot/chromium.linux.json

 {
   "Android Arm64 Builder (dbg)": {
     "additional_compile_targets": [
       "all"
     ]
   },
   "Android Builder": {
     "additional_compile_targets": [
       "cronet_test_instrumentation_apk",
       "system_webview_apk"
@@ skipping 1039 matching lines @@
         },
         "test": "compositor_unittests"
       },
       {
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "content_browsertests"
       },
       {
+        "args": [
+          "--enable-browser-side-navigation",
+          "--test-launcher-filter-file=../../testing/buildbot/filters/browser-side-navigation.linux.content_browsertests.filter"
+        ],
+        "name": "browser_side_navigation_content_browsertests",
+        "swarming": {
+          "can_use_on_swarming_builders": true
+        },
+        "test": "content_browsertests"
+      },
+      {
         "override_compile_targets": [
           "content_site_isolation_browsertests"
         ],
         "swarming": {
           "can_use_on_swarming_builders": true
         },
         "test": "content_site_isolation_browsertests"
       },
       {
         "swarming": {
@@ skipping 1154 matching lines @@
         "override_compile_targets": [
           "telemetry_unittests_run"
         ],
         "swarming": {
           "can_use_on_swarming_builders": true
         }
       }
     ]
   }
 }