Implement EssentialSearchEnabled policy

EssentialSearchEnabled policy is responsible for letting admins control
how Google processes cookies and data sent to Search. This policy is
expected to work in both ChromeOS Ash and ChromeOS Lacros.

Bug: b/312542928
Change-Id: I93702454cc2e94d7c4e78d956b52e54a2678dcc4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5172585
Reviewed-by: Avi Drissman <[email protected]>
Commit-Queue: Mohammed Abdon <[email protected]>
Code-Coverage: [email protected] <[email protected]>
Reviewed-by: Maksim Ivanov <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1244910}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 7a6e93f..58ca863 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -1854,6 +1854,7 @@
   registry->RegisterBooleanPref(prefs::kDeskAPIDeskSaveAndShareEnabled, false);
   registry->RegisterListPref(prefs::kDeskAPIThirdPartyAllowlist);
   registry->RegisterBooleanPref(prefs::kInsightsExtensionEnabled, false);
+  registry->RegisterBooleanPref(prefs::kEssentialSearchEnabled, false);
   // By default showing Sync Consent is set to true. It can changed by policy.
   registry->RegisterBooleanPref(prefs::kEnableSyncConsent, true);
   registry->RegisterListPref(