Prevent GetDeviceId from invoking its callback multiple times in failure cases.

chrome/browser/prefs/pref_metrics_service.h

Index: chrome/browser/prefs/pref_metrics_service.h
diff --git a/chrome/browser/prefs/pref_metrics_service.h b/chrome/browser/prefs/pref_metrics_service.h
index 3a4bc4fcbc358d65a2823a3a3095113b6cc0795c..b50b1c018bc422a4353e352c34303ebde7ad154b 100644
--- a/chrome/browser/prefs/pref_metrics_service.h
+++ b/chrome/browser/prefs/pref_metrics_service.h
@@ -121,7 +121,10 @@ class PrefMetricsService : public BrowserContextKeyedService {
   std::string device_id_;
   const char** tracked_pref_paths_;
   const int tracked_pref_path_count_;
+
+#if defined(ENABLE_DCHECK)

[Bernhard Bauer, 2013/11/22 09:55:03]

Does this work? It seems ENABLE_DCHECK is #undef'd again in logging.h
(https://code.google.com/p/chromium/codesearch#chromium/src/base/logging.h&sq=...).
I'm not sure there is currently a #define that is defined iff DCHECKs are
compiled in :-(

[gab, 2013/11/22 21:05:13]

Ah, good point... I think
#if !defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)
would do it (see patch set 3), but it feels like it relies on implementation
details too much...

I removed them for now (sadly keeping a class member around in official builds
which is only used for a DCHECK...).

Please let me know what you think.

Cheers,
Gab

[Bernhard Bauer, 2013/11/22 21:53:55]

I think what we should do is add a #define for this.

For now, can you add a TODO to #ifdef the field out once we have a define? (And
possibly reference a bug)

   bool checked_tracked_prefs_;
+#endif
 
   PrefChangeRegistrar pref_registrar_;
   scoped_ptr<SyncedPrefChangeRegistrar> synced_pref_change_registrar_;