Fix adding duplicate trials to allocator (finally)

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 <utility>
 
 #include "base/base_switches.h"
@@ skipping 344 matching lines @@
 void FieldTrial::FinalizeGroupChoiceImpl(bool is_locked) {
   if (group_ != kNotFinalized)
     return;
   accumulated_group_probability_ = divisor_;
   // Here it's OK to use |kDefaultGroupNumber| since we can't be forced and not
   // finalized.
   DCHECK(!forced_);
   SetGroupChoice(default_group_name_, kDefaultGroupNumber);
 
   // Add the field trial to shared memory.
-  if (kUseSharedMemoryForFieldTrials)
+  if (kUseSharedMemoryForFieldTrials && trial_registered_)
     FieldTrialList::OnGroupFinalized(is_locked, this);
 }
 
 bool FieldTrial::GetActiveGroup(ActiveGroup* active_group) const {
   if (!group_reported_ || !enable_field_trial_)
     return false;
   DCHECK_NE(group_, kNotFinalized);
   active_group->trial_name = trial_name_;
   active_group->group_name = group_name_;
   return true;
@@ skipping 634 matching lines @@
     return;
   }
   AutoLock auto_lock(global_->lock_);
   CHECK(!global_->PreLockedFind(trial->trial_name())) << trial->trial_name();
   trial->AddRef();
   trial->SetTrialRegistered();
   global_->registered_[trial->trial_name()] = trial;
 }
 
 }  // namespace base