Rewrite scoped_ptr<T>(NULL) to use the default ctor in chrome/.

chrome/browser/extensions/test_extension_prefs.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/extensions/test_extension_prefs.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 40 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(IncrementalTimeProvider);
 
   mutable base::Time current_time_;
 };
 
 }  // namespace
 
 TestExtensionPrefs::TestExtensionPrefs(base::SequencedTaskRunner* task_runner)
-    : pref_service_(NULL),
-      task_runner_(task_runner),
-      extensions_disabled_(false) {
+    : task_runner_(task_runner), extensions_disabled_(false) {
   EXPECT_TRUE(temp_dir_.CreateUniqueTempDir());
   preferences_file_ = temp_dir_.path().AppendASCII("Preferences");
   extensions_dir_ = temp_dir_.path().AppendASCII("Extensions");
   EXPECT_TRUE(file_util::CreateDirectory(extensions_dir_));
 
   ResetPrefRegistry();
   RecreateExtensionPrefs();
 }
 
 TestExtensionPrefs::~TestExtensionPrefs() {
@@ skipping 101 matching lines @@
 PrefService* TestExtensionPrefs::CreateIncognitoPrefService() const {
   return pref_service_->CreateIncognitoPrefService(
       new ExtensionPrefStore(extension_pref_value_map_.get(), true));
 }
 
 void TestExtensionPrefs::set_extensions_disabled(bool extensions_disabled) {
   extensions_disabled_ = extensions_disabled;
 }
 
 }  // namespace extensions