Update UKM Sync checks.

This changed the datatype checks from GetPreferredDataTypes to GetActiveDataTypes and adds IsSyncFeatureActive() check instead of connection_status.

Tested end-to-end verified against the butter experiment.

Bug: 906609
Change-Id: I23c0f80cf707a1e8cca5b3f2aa99a3aebc6eec94
Reviewed-on: https://chromium-review.googlesource.com/c/1343369
Commit-Queue: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610100}

components/ukm/observers/sync_disable_observer.cc

@@ -21,6 +21,8 @@ namespace ukm {
 
 const base::Feature kUkmCheckAuthErrorFeature{"UkmCheckAuthError",
                                               base::FEATURE_ENABLED_BY_DEFAULT};
+const base::Feature kUkmCheckEnabledForDatatypes{
+    "UkmCheckEnabledForDatatypes", base::FEATURE_ENABLED_BY_DEFAULT};
 const base::Feature kUkmPurgingOnConnection{"UkmPurgingOnConnection",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 
@@ -79,13 +81,37 @@ SyncDisableObserver::SyncState SyncDisableObserver::GetSyncState(
     UrlKeyedDataCollectionConsentHelper* consent_helper) {
   syncer::SyncTokenStatus status = sync_service->GetSyncTokenStatus();
   SyncState state;
-  state.history_enabled = sync_service->GetPreferredDataTypes().Has(
-      syncer::HISTORY_DELETE_DIRECTIVES);
-  state.extensions_enabled =
-      sync_service->GetPreferredDataTypes().Has(syncer::EXTENSIONS);
+
+  // For the following two settings, we want them to match the state of a user
+  // having history/extensions enabled in their Sync settings. Using it to track
+  // active connections here is undesirable as changes in these states trigger
+  // data purges.
+  if (base::FeatureList::IsEnabled(kUkmCheckEnabledForDatatypes)) {
+    state.history_enabled = sync_service->GetPreferredDataTypes().Has(
+                                syncer::HISTORY_DELETE_DIRECTIVES) &&
+                            sync_service->IsSyncFeatureEnabled();
+
+    state.extensions_enabled =
+        sync_service->GetPreferredDataTypes().Has(syncer::EXTENSIONS) &&
+        sync_service->IsSyncFeatureEnabled();
+  } else {
+    // If kUkmCheckEnabledForDatatypes is disabled, use legacy settings.
+    // TODO(rkaplow): Clean this up after crbug.com/906609.
+    state.history_enabled = sync_service->GetPreferredDataTypes().Has(
+        syncer::HISTORY_DELETE_DIRECTIVES);
+
+    state.extensions_enabled =
+        sync_service->GetPreferredDataTypes().Has(syncer::EXTENSIONS);
+  }
+
   state.initialized = sync_service->IsEngineInitialized();
+
+  // We use CONNECTION_OK here as an auth error can be used in the sync
+  // paused state. Therefore we need to be more direct and check CONNECTION_OK
+  // as opposed to using something like IsSyncFeatureActive().
   state.connected = !base::FeatureList::IsEnabled(kUkmCheckAuthErrorFeature) ||
                     status.connection_status == syncer::CONNECTION_OK;
+
   state.passphrase_protected =
       state.initialized && sync_service->IsUsingSecondaryPassphrase();
   if (consent_helper) {