Introduce --vr-shell flag on Android

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 7a68be2e2bcc8f2cdf5caf63f663a693cd7714f1..3c41263dd54d5429c2e201acf9701619df740ff9 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -79205,10 +79205,12 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-495585885" label="enable-spdy-proxy-dev-auth-origin"/>
   <int value="-488779992" label="blink-settings"/>
   <int value="-478462945" label="enable-ephemeral-apps"/>
+  <int value="-475049740" label="disable-vr-shell"/>
   <int value="-462205750" label="enable-service-worker-sync"/>
   <int value="-455203267" label="use_new_features_summary"/>
   <int value="-430360431" label="disable-password-generation"/>
   <int value="-418868128" label="enable-experimental-web-platform-features"/>
+  <int value="-396994784" label="enable-vr-shell"/>
   <int value="-385337473" label="enable-fast-unload"/>
   <int value="-384589459" label="disable-supervised-user-safesites"/>
   <int value="-378180863" label="disable-panels"/>