Cleanup usage of scoped_ptr<> in remoting for C++11

remoting/host/policy_hack/policy_watcher_linux.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.
 
 // Most of this code is copied from various classes in
 // src/chrome/browser/policy. In particular, look at
 //
 //   file_based_policy_loader.{h,cc}
 //   config_dir_policy_provider.{h,cc}
 //
@@ skipping 131 matching lines @@
          config_file_iter != files.end(); ++config_file_iter) {
       JSONFileValueSerializer deserializer(*config_file_iter);
       deserializer.set_allow_trailing_comma(true);
       int error_code = 0;
       std::string error_msg;
       scoped_ptr<base::Value> value(
           deserializer.Deserialize(&error_code, &error_msg));
       if (!value.get()) {
         LOG(WARNING) << "Failed to read configuration file "
                      << config_file_iter->value() << ": " << error_msg;
-        return scoped_ptr<base::DictionaryValue>();
+        return nullptr;
       }
       if (!value->IsType(base::Value::TYPE_DICTIONARY)) {
         LOG(WARNING) << "Expected JSON dictionary in configuration file "
                      << config_file_iter->value();
-        return scoped_ptr<base::DictionaryValue>();
+        return nullptr;
       }
       policy->MergeDictionary(static_cast<base::DictionaryValue*>(value.get()));
     }
 
     return policy.Pass();
   }
 
   virtual void Reload() OVERRIDE {
     DCHECK(OnPolicyWatcherThread());
     // Check the directory time in order to see whether a reload is required.
@@ skipping 77 matching lines @@
 };
 
 PolicyWatcher* PolicyWatcher::Create(
     scoped_refptr<base::SingleThreadTaskRunner> task_runner) {
   base::FilePath policy_dir(kPolicyDir);
   return new PolicyWatcherLinux(task_runner, policy_dir);
 }
 
 }  // namespace policy_hack
 }  // namespace remoting