Remove unnecessary comment in metrics code

components/metrics/metrics_state_manager.cc

Index: components/metrics/metrics_state_manager.cc
diff --git a/components/metrics/metrics_state_manager.cc b/components/metrics/metrics_state_manager.cc
index ae0754e8ea1134b9e8ddcacca676ccb0c7772394..5abbf7e32fc1bef375b69e2e834b20b0031845be 100644
--- a/components/metrics/metrics_state_manager.cc
+++ b/components/metrics/metrics_state_manager.cc
@@ -261,10 +261,7 @@ MetricsStateManager::LoadClientInfoAndMaybeMigrate() {
   }
 
   // The GUID retrieved (and possibly fixed above) should be valid unless
-  // retrieval failed.
-  // DCHECK(!client_info || base::IsValidGUID(client_info->client_id));
-  // Temporary hack for http://crbug.com/635255.
-  // TODO(asvitkine): address this the right way.
+  // retrieval failed. If not, return nullptr and generate a new GUID.

[Alexei Svitkine (slow), 2016/09/13 17:38:36]

"and generate a new GUID" part of the comment is confusing, because that's not
being done in this function.

I suggest expanding the comment to give more context, like ". This will result
in a new GUID being generated and backed up by the calling code FooBar()."

   if (client_info && !base::IsValidGUID(client_info->client_id))
     return nullptr;