Replace NULL with nullptr or null in webrtc/base/.

webrtc/base/taskparent.cc

 /*
  *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #include <algorithm>
 
 #include "webrtc/base/taskparent.h"
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/task.h"
 #include "webrtc/base/taskrunner.h"
 
 namespace rtc {
 
 TaskParent::TaskParent(Task* derived_instance, TaskParent *parent)
     : parent_(parent) {
-  RTC_DCHECK(derived_instance != NULL);
-  RTC_DCHECK(parent != NULL);
+  RTC_DCHECK(derived_instance != nullptr);
+  RTC_DCHECK(parent != nullptr);
   runner_ = parent->GetRunner();
   parent_->AddChild(derived_instance);
   Initialize();
 }
 
-TaskParent::TaskParent(TaskRunner *derived_instance)
-    : parent_(NULL),
-      runner_(derived_instance) {
-  RTC_DCHECK(derived_instance != NULL);
+TaskParent::TaskParent(TaskRunner* derived_instance)
+    : parent_(nullptr), runner_(derived_instance) {
+  RTC_DCHECK(derived_instance != nullptr);
   Initialize();
 }
 
 TaskParent::~TaskParent() = default;
 
 // Does common initialization of member variables
 void TaskParent::Initialize() {
   children_.reset(new ChildSet());
   child_error_ = false;
 }
 
 void TaskParent::AddChild(Task *child) {
   children_->insert(child);
 }
 
 #if RTC_DCHECK_IS_ON
 bool TaskParent::IsChildTask(Task *task) {
-  RTC_DCHECK(task != NULL);
+  RTC_DCHECK(task != nullptr);
   return task->parent_ == this && children_->find(task) != children_->end();
 }
 #endif
 
 bool TaskParent::AllChildrenDone() {
   for (ChildSet::iterator it = children_->begin();
        it != children_->end();
        ++it) {
     if (!(*it)->IsDone())
       return false;
@@ skipping 27 matching lines @@
   parent_->OnChildStopped(task);
 }
 
 void TaskParent::OnChildStopped(Task *child) {
   if (child->HasError())
     child_error_ = true;
   children_->erase(child);
 }
 
 } // namespace rtc