UserEventServiceImpl: Check IsSyncFeatureEnabled

If IsSyncFeatureEnabled is false, then GetPreferredDataTypes doesn't
really mean anything.
In practice, this wasn't an actual issue: If Sync isn't enabled, then
the whole UserEventService can't upload anything anyway. But still best
to be precise here.

Bug: 907027, 856081
Change-Id: I2e3ee7200118175ed9397b5a1b7d9fedd0eb7692
Reviewed-on: https://chromium-review.googlesource.com/c/1344104Reviewed-by: vitaliii <vitaliii@chromium.org>
Commit-Queue: Marc Treib <treib@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610022}

components/sync/user_events/user_event_service_impl.cc

@@ -101,19 +101,22 @@ bool UserEventServiceImpl::MightRecordEvents(bool off_the_record,
 }
 
 bool UserEventServiceImpl::CanRecordHistory() {
-  // Before the engine is initialized, we cannot trust the other fields.
-  // TODO(vitaliii): Consider using GetState() instead of IsEngineInitialized(),
-  // because even when IsEngineInitialized() the user still may be configuring
-  // the datatypes.
+  // Before the engine is initialized, Sync doesn't know if there is a
+  // secondary passphrase. Similarly, unless the Sync feature is enabled,
+  // GetPreferredDataTypes() isn't meaningful.
   return sync_service_->IsEngineInitialized() &&
          !sync_service_->IsUsingSecondaryPassphrase() &&
+         sync_service_->IsSyncFeatureEnabled() &&
          sync_service_->GetPreferredDataTypes().Has(HISTORY_DELETE_DIRECTIVES);
 }
 
 bool UserEventServiceImpl::IsUserEventsDatatypeEnabled() {
-  // Before the engine is initialized, we cannot trust the other fields.
+  // Before the engine is initialized, Sync doesn't know if there is a
+  // secondary passphrase. Similarly, unless the Sync feature is enabled,
+  // GetPreferredDataTypes() isn't meaningful.
   return sync_service_->IsEngineInitialized() &&
          !sync_service_->IsUsingSecondaryPassphrase() &&
+         sync_service_->IsSyncFeatureEnabled() &&
          sync_service_->GetPreferredDataTypes().Has(USER_EVENTS);
 }