Omnibox UI Experiments: Add flag to change max autocomplete matches.

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 0eb13d53bf801928b4e550de298883a7baed0972..9dc1cf120db83df9f821d0a7308cc8bec3636fbb 100644
--- a/tools/metrics/histograms/enums.xml
+++ b/tools/metrics/histograms/enums.xml
@@ -21770,6 +21770,8 @@ from previous Chrome versions.
   <int value="98134240" label="material-design-ink-drop-animation-speed"/>
   <int value="103932290" label="show-autofill-type-predictions"/>
   <int value="118991027" label="enable-accelerated-fixed-root-background"/>
+  <int value="119185738"
+      label="OmniboxUIExperimentMaxAutocompleteMatches:disabled"/>
   <int value="120429808" label="disable-new-profile-management"/>
   <int value="121684313" label="QuickUnlockPin:enabled"/>
   <int value="121858954" label="enable-supervised-user-safesites"/>
@@ -22044,6 +22046,8 @@ from previous Chrome versions.
   <int value="1166169237" label="disable-delay-agnostic-aec"/>
   <int value="1167613030" label="enable-permission-action-reporting"/>
   <int value="1174088940" label="enable-wasm"/>
+  <int value="1179013979"
+      label="OmniboxUIExperimentMaxAutocompleteMatches:enabled"/>
   <int value="1179936481" label="enable-android-pay-integration-v1"/>
   <int value="1181056275" label="enable-cloud-backup"/>
   <int value="1183431946" label="v8-cache-options"/>