Add new opt guide store with support for load/update

This CL introduces the new model store that allows models to be shared across
userprofiles. The store supports load and update operations.

The old store still is used by the prediction manager, and subsequent CLs
will make it use the new store.

Bug: b:244649670
Bug: 1386205
Change-Id: Ie785d0bf06f4c47c4c84bcbfc15b4df1c3fd1fef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4027993
Reviewed-by: Sophie Chang <[email protected]>
Reviewed-by: Scott Violet <[email protected]>
Commit-Queue: Raj T <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1074175}
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 4d35e3380..a92551b9 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -1066,6 +1066,7 @@
   memory::EnterpriseMemoryLimitPrefObserver::RegisterPrefs(registry);
   metrics::RegisterDemographicsLocalStatePrefs(registry);
   network_time::NetworkTimeTracker::RegisterPrefs(registry);
+  optimization_guide::prefs::RegisterLocalStatePrefs(registry);
   password_manager::PasswordManager::RegisterLocalPrefs(registry);
   policy::BrowserPolicyConnector::RegisterPrefs(registry);
   policy::ManagementService::RegisterLocalStatePrefs(registry);