[unified-consent] Configure sync when engine is initialized

Already configure sync in the UnifiedConsentService when the
sync engine is initialized, instead of waiting for sync to be
active.

Bug: 891706
Change-Id: I4f072e56820784f42ce9f2033724e43d8d5f5bf3
Reviewed-on: https://chromium-review.googlesource.com/c/1264656Reviewed-by: Marc Treib <treib@chromium.org>
Commit-Queue: Thomas Tangl <tangltom@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597099}

components/unified_consent/unified_consent_service.cc

@@ -311,16 +311,8 @@ void UnifiedConsentService::OnStateChanged(syncer::SyncService* sync) {
 
   syncer::SyncPrefs sync_prefs(pref_service_);
   if (IsUnifiedConsentGiven() != sync_prefs.HasKeepEverythingSynced()) {
-    // |OnStateChanged| is called after every update in the sync service,
-    // therefore only allow to update the sync settings when the transport
-    // state is ACTIVE.
-    // Note: This is a safety measure. Theoretically this can be done when
-    // the sync engine is initialized.
-    if (sync_service_->GetTransportState() ==
-        syncer::SyncService::TransportState::ACTIVE) {
-      // Make sync-everything consistent with the |kUnifiedConsentGiven| pref.
-      PostTaskToUpdateSyncSettings(/*sync_everything=*/IsUnifiedConsentGiven());
-    }
+    // Make sync-everything consistent with the |kUnifiedConsentGiven| pref.
+    PostTaskToUpdateSyncSettings(/*sync_everything=*/IsUnifiedConsentGiven());
   }
 }
 
@@ -452,8 +444,7 @@ void UnifiedConsentService::MigrateProfileToUnifiedConsent() {
 }
 
 void UnifiedConsentService::UpdateSettingsForMigration() {
-  if (sync_service_->GetTransportState() !=
-      syncer::SyncService::TransportState::ACTIVE) {
+  if (!sync_service_->IsEngineInitialized()) {
     SetMigrationState(MigrationState::kInProgressWaitForSyncInit);
     return;
   }

components/unified_consent/unified_consent_service_unittest.cc

@@ -384,7 +384,7 @@ TEST_F(UnifiedConsentServiceTest, Migration_SyncingEverythingAndAllServicesOn) {
   EXPECT_TRUE(sync_prefs.HasKeepEverythingSynced());
   EXPECT_FALSE(pref_service_.GetBoolean(prefs::kUnifiedConsentGiven));
   sync_service_.SetTransportState(
-      syncer::SyncService::TransportState::PENDING_DESIRED_CONFIGURATION);
+      syncer::SyncService::TransportState::INITIALIZING);
   EXPECT_FALSE(sync_service_.IsSyncFeatureActive());
 
   CreateConsentService(true /* client_services_on_by_default */);