Temporary hack to fix telemetry_perf_unittests flakes.

components/metrics/metrics_state_manager.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/metrics/metrics_state_manager.h"
 
 #include <stddef.h>
 
 #include "base/command_line.h"
 #include "base/guid.h"
@@ skipping 239 matching lines @@
         client_id_with_dashes.push_back(*client_id_it);
         ++client_id_it;
       }
     }
     DCHECK(client_id_it == client_info->client_id.end());
     client_info->client_id.assign(client_id_with_dashes);
   }
 
   // The GUID retrieved (and possibly fixed above) should be valid unless
   // retrieval failed.
-  DCHECK(!client_info || base::IsValidGUID(client_info->client_id));
+  // DCHECK(!client_info || base::IsValidGUID(client_info->client_id));
+  // Temporary hack for http://crbug.com/635255.
+  // TODO(asvitkine): address this the right way.
+  if (client_info && !base::IsValidGUID(client_info->client_id))
+    return nullptr;
 
   return client_info;
 }
 
 int MetricsStateManager::GetLowEntropySource() {
   UpdateLowEntropySource();
   return low_entropy_source_;
 }
 
 void MetricsStateManager::UpdateLowEntropySource() {
@@ skipping 46 matching lines @@
 
   local_state_->ClearPref(prefs::kMetricsClientID);
   local_state_->ClearPref(prefs::kMetricsLowEntropySource);
   local_state_->ClearPref(prefs::kMetricsResetIds);
 
   // Also clear the backed up client info.
   store_client_info_.Run(ClientInfo());
 }
 
 }  // namespace metrics