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

chrome/browser/extensions/api/webstore_private/webstore_private_api.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/api/webstore_private/webstore_private_api.h"
 
 #include "apps/app_launcher.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 68 matching lines @@
 scoped_ptr<WebstoreInstaller::Approval> PendingApprovals::PopApproval(
     Profile* profile, const std::string& id) {
   for (size_t i = 0; i < approvals_.size(); ++i) {
     WebstoreInstaller::Approval* approval = approvals_[i];
     if (approval->extension_id == id &&
         profile->IsSameProfile(approval->profile)) {
       approvals_.weak_erase(approvals_.begin() + i);
       return scoped_ptr<WebstoreInstaller::Approval>(approval);
     }
   }
-  return scoped_ptr<WebstoreInstaller::Approval>(NULL);
+  return scoped_ptr<WebstoreInstaller::Approval>();
 }
 
 // Uniquely holds the profile and extension id of an install between the time we
 // prompt and complete the installs.
 class PendingInstalls {
  public:
   PendingInstalls();
   ~PendingInstalls();
 
   bool InsertInstall(Profile* profile, const std::string& id);
@@ skipping 609 matching lines @@
   SendResponse(true);
 }
 
 bool GetIsLauncherEnabledFunction::RunImpl() {
   SetResult(Value::CreateBooleanValue(apps::IsAppLauncherEnabled()));
   SendResponse(true);
   return true;
 }
 
 }  // namespace extensions