Add AppRTCMobileTestStubbedVideoIO to gn_isolate_map.

tools-webrtc/mb/gn_isolate_map.pyl

Index: tools-webrtc/mb/gn_isolate_map.pyl
diff --git a/tools-webrtc/mb/gn_isolate_map.pyl b/tools-webrtc/mb/gn_isolate_map.pyl
index 7ab32ed8b63b9df5f639096e6c0ec5c72a52b7f3..68e8032c6cfd007e8bd0e1ed8e341d6c3e8d4c0e 100644
--- a/tools-webrtc/mb/gn_isolate_map.pyl
+++ b/tools-webrtc/mb/gn_isolate_map.pyl
@@ -23,6 +23,10 @@
     "label": "//webrtc/examples:AppRTCMobileTest",
     "type": "additional_compile_target",
   },
+  "AppRTCMobileTestStubbedVideoIO": {
+    "label": "//webrtc/examples:AppRTCMobileTestStubbedVideoIO",
+    "type": "additional_compile_target",
+  },
   "android_junit_tests": {
     "label": "//webrtc:android_junit_tests",
     "type": "junit_test",