Add flag for single click autofill

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 e56ebe64edce72e919c93cad1cc2ff8b212c6ec1..b1356ea7d1bb812a142c5ef2d4d356069171677f 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -48783,6 +48783,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-820041355" label="enable-transition-compositing"/>
   <int value="-814097014" label="disable-session-crashed-bubble"/>
   <int value="-795600188" label="disable-async-dns"/>
+  <int value="-780798969" label="disable-single-click-autofill"/>
   <int value="-770319039" label="enable-touch-editing"/>
   <int value="-749048160" label="enable-panels"/>
   <int value="-744159181" label="disable-spdy-proxy-dev-auth-origin"/>
@@ -48833,6 +48834,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="-80353187" label="disable-display-color-calibration"/>
   <int value="-76631048" label="disable-offline-auto-reload-visible-only"/>
   <int value="-68225452" label="enable-translate-new-ux"/>
+  <int value="-52241456" label="enable-single-click-autofill"/>
   <int value="-48920737" label="enable-smooth-scrolling"/>
   <int value="-23090520" label="disable-search-button-in-omnibox"/>
   <int value="-22544408" label="enable-video-player-chromecast-support"/>