Omnibox UI Experiments: Add Vertical Layout experiment (title-on-top).

tools/metrics/histograms/enums.xml

Index: tools/metrics/histograms/enums.xml
diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
index 3414618e1dd1e52ecd9b9ba92d977a3571cac4f3..0ab351225cb75d972cd721284e0e0a62aea63e4d 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -21416,6 +21416,7 @@ uploading your change for review.  These are checked by presubmit scripts.
   <int value="-1463410070" label="IPH_DemoMode:enabled"/>
   <int value="-1460462432" label="disable-media-source"/>
   <int value="-1456004000" label="VrShell:disabled"/>
+  <int value="-1450576851" label="OmniboxUIExperimentVerticalLayout:enabled"/>
   <int value="-1443796945" label="OfflinePagesSharing:disabled"/>
   <int value="-1440440375" label="WebVrAutopresent:enabled"/>
   <int value="-1440152291" label="disable-gesture-typing"/>
@@ -22175,6 +22176,7 @@ from previous Chrome versions.
   <int value="1318073661" label="MaterialDesignExtensions:enabled"/>
   <int value="1319725131" label="enable-distance-field-text"/>
   <int value="1320201920" label="enable-touchpad-three-finger-click"/>
+  <int value="1330264457" label="OmniboxUIExperimentVerticalLayout:disabled"/>
   <int value="1344833841" label="ImeThread:enabled"/>
   <int value="1351830811" label="do-not-ignore-autocomplete-off"/>
   <int value="1352447982" label="enable-lcd-text"/>