Convert FieldTrialList to Accept a std::unique_ptr

chrome/browser/safe_browsing/client_side_model_loader_unittest.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/safe_browsing/client_side_model_loader.h"
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
@@ skipping 36 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockModelLoader);
 };
 
 }  // namespace
 
 class ModelLoaderTest : public testing::Test {
  protected:
   ModelLoaderTest()
-      : factory_(new net::FakeURLFetcherFactory(NULL)),
-        field_trials_(new base::FieldTrialList(NULL)) {}
+      : factory_(new net::FakeURLFetcherFactory(nullptr)),
+        field_trials_(new base::FieldTrialList(nullptr)) {}
 
   void SetUp() override {
     variations::testing::ClearAllVariationIDs();
     variations::testing::ClearAllVariationParams();
   }
 
   // Set up the finch experiment to control the model number
   // used in the model URL. This clears all existing state.
   void SetFinchModelNumber(int model_number) {
     // Destroy the existing FieldTrialList before creating a new one to avoid
     // a DCHECK.
     field_trials_.reset();
-    field_trials_.reset(new base::FieldTrialList(NULL));
+    field_trials_.reset(new base::FieldTrialList(nullptr));
     variations::testing::ClearAllVariationIDs();
     variations::testing::ClearAllVariationParams();
 
     const std::string group_name = "ModelFoo";  // Not used in CSD code.
     ASSERT_TRUE(base::FieldTrialList::CreateFieldTrial(
         ModelLoader::kClientModelFinchExperiment, group_name));
 
     std::map<std::string, std::string> params;
     params[ModelLoader::kClientModelFinchParam] =
         base::IntToString(model_number);
@@ skipping 255 matching lines @@
   EXPECT_FALSE(ModelLoader::ModelHasValidHashIds(model));
 
   rule->set_feature(2, 2);
   EXPECT_FALSE(ModelLoader::ModelHasValidHashIds(model));
 
   rule->set_feature(2, 1);
   EXPECT_TRUE(ModelLoader::ModelHasValidHashIds(model));
 }
 
 }  // namespace safe_browsing