Refactor safe-browsing build-config definitions.

chrome/browser/safe_browsing/safe_browsing_service.h

Index: chrome/browser/safe_browsing/safe_browsing_service.h
diff --git a/chrome/browser/safe_browsing/safe_browsing_service.h b/chrome/browser/safe_browsing/safe_browsing_service.h
index 2fbfbc37b498ae6cdb4a33fc4b23858f43d31255..3431e9c7061e72e527b680fb00a50167d99f8484 100644
--- a/chrome/browser/safe_browsing/safe_browsing_service.h
+++ b/chrome/browser/safe_browsing/safe_browsing_service.h
@@ -216,6 +216,9 @@ class SafeBrowsingService
   // Used to track creation and destruction of profiles on the UI thread.
   content::NotificationRegistrar prefs_registrar_;
 
+  // TODO(shess): Should csd_service_ be guarded by SAFE_BROWSING_CSD?  Likewise
+  // for download_service_ and incident_service_?
+
   // The ClientSideDetectionService is managed by the SafeBrowsingService,
   // since its running state and lifecycle depends on SafeBrowsingService's.
   // Accessed on UI thread.