Add more debugging CHECKS to diagnose an Android renderer crash.

base/metrics/field_trial.cc

 // Copyright (c) 2012 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 "base/metrics/field_trial.h"
 
 #include <algorithm>
 
 #include "base/build_time.h"
 #include "base/logging.h"
@@ skipping 620 matching lines @@
   return it->second;
 }
 
 // static
 void FieldTrialList::Register(FieldTrial* trial) {
   if (!global_) {
     used_without_global_ = true;
     return;
   }
   AutoLock auto_lock(global_->lock_);
-  DCHECK(!global_->PreLockedFind(trial->trial_name()));
+  CHECK(!global_->PreLockedFind(trial->trial_name())) << trial->trial_name();
   trial->AddRef();
   trial->SetTrialRegistered();
   global_->registered_[trial->trial_name()] = trial;
 }
 
 }  // namespace base