Convert FieldTrialList to Accept a std::unique_ptr

chrome/browser/chrome_browser_main.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 "chrome/browser/chrome_browser_main.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 781 matching lines @@
 
 // This will be called after the command-line has been mutated by about:flags
 void ChromeBrowserMainParts::SetupFieldTrials() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::SetupFieldTrials");
 
   // Initialize FieldTrialList to support FieldTrials that use one-time
   // randomization.
   DCHECK(!field_trial_list_);
   field_trial_list_.reset(
       new base::FieldTrialList(browser_process_->GetMetricsServicesManager()
-                                   ->CreateEntropyProvider()
-                                   .release()));
+                                   ->CreateEntropyProvider()));
 
   const base::CommandLine* command_line =
       base::CommandLine::ForCurrentProcess();
   if (command_line->HasSwitch(switches::kEnableBenchmarking) ||
       command_line->HasSwitch(cc::switches::kEnableGpuBenchmarking)) {
     base::FieldTrial::EnableBenchmarking();
   }
 
   if (command_line->HasSwitch(switches::kForceFieldTrialParams)) {
     bool result = chrome_variations::AssociateParamsFromString(
@@ skipping 1402 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }