diff --git a/atom/browser/api/atom_api_menu.cc b/atom/browser/api/atom_api_menu.cc
index 5e66850c7542..54a3d4e81326 100644
--- a/atom/browser/api/atom_api_menu.cc
+++ b/atom/browser/api/atom_api_menu.cc
@@ -21,7 +21,7 @@ namespace api {
 
 Menu::Menu(v8::Isolate* isolate)
     : model_(new AtomMenuModel(this)),
-      parent_(NULL) {
+      parent_(nullptr) {
 }
 
 Menu::~Menu() {
diff --git a/atom/browser/api/event.cc b/atom/browser/api/event.cc
index 2554e4ad0dab..8c60eda24713 100644
--- a/atom/browser/api/event.cc
+++ b/atom/browser/api/event.cc
@@ -12,8 +12,8 @@
 namespace mate {
 
 Event::Event(v8::Isolate* isolate)
-    : sender_(NULL),
-      message_(NULL) {
+    : sender_(nullptr),
+      message_(nullptr) {
   Init(isolate);
 }
 
@@ -31,8 +31,8 @@ void Event::SetSenderAndMessage(content::WebContents* sender,
 }
 
 void Event::WebContentsDestroyed() {
-  sender_ = NULL;
-  message_ = NULL;
+  sender_ = nullptr;
+  message_ = nullptr;
 }
 
 void Event::PreventDefault(v8::Isolate* isolate) {
@@ -41,13 +41,13 @@ void Event::PreventDefault(v8::Isolate* isolate) {
 }
 
 bool Event::SendReply(const base::string16& json) {
-  if (message_ == NULL || sender_ == NULL)
+  if (message_ == nullptr || sender_ == nullptr)
     return false;
 
   AtomViewHostMsg_Message_Sync::WriteReplyParams(message_, json);
   bool success = sender_->Send(message_);
-  message_ = NULL;
-  sender_ = NULL;
+  message_ = nullptr;
+  sender_ = nullptr;
   return success;
 }
 
diff --git a/atom/browser/atom_browser_main_parts.cc b/atom/browser/atom_browser_main_parts.cc
index b933d1073bb6..66c1bd8303ad 100644
--- a/atom/browser/atom_browser_main_parts.cc
+++ b/atom/browser/atom_browser_main_parts.cc
@@ -32,7 +32,7 @@ void Erase(T* container, typename T::iterator iter) {
 }
 
 // static
-AtomBrowserMainParts* AtomBrowserMainParts::self_ = NULL;
+AtomBrowserMainParts* AtomBrowserMainParts::self_ = nullptr;
 
 AtomBrowserMainParts::AtomBrowserMainParts()
     : fake_browser_process_(new BrowserProcess),
diff --git a/atom/browser/atom_browser_main_parts_posix.cc b/atom/browser/atom_browser_main_parts_posix.cc
index 2a0dddc47483..8c96f91bfe68 100644
--- a/atom/browser/atom_browser_main_parts_posix.cc
+++ b/atom/browser/atom_browser_main_parts_posix.cc
@@ -43,7 +43,7 @@ void GracefulShutdownHandler(int signal) {
   struct sigaction action;
   memset(&action, 0, sizeof(action));
   action.sa_handler = SIG_DFL;
-  RAW_CHECK(sigaction(signal, &action, NULL) == 0);
+  RAW_CHECK(sigaction(signal, &action, nullptr) == 0);
 
   RAW_CHECK(g_pipe_pid == getpid());
   RAW_CHECK(g_shutdown_pipe_write_fd != -1);
@@ -171,7 +171,7 @@ void AtomBrowserMainParts::HandleSIGCHLD() {
   struct sigaction action;
   memset(&action, 0, sizeof(action));
   action.sa_handler = SIGCHLDHandler;
-  CHECK_EQ(sigaction(SIGCHLD, &action, NULL), 0);
+  CHECK_EQ(sigaction(SIGCHLD, &action, nullptr), 0);
 }
 
 void AtomBrowserMainParts::HandleShutdownSignals() {
@@ -211,15 +211,15 @@ void AtomBrowserMainParts::HandleShutdownSignals() {
   struct sigaction action;
   memset(&action, 0, sizeof(action));
   action.sa_handler = SIGTERMHandler;
-  CHECK_EQ(sigaction(SIGTERM, &action, NULL), 0);
+  CHECK_EQ(sigaction(SIGTERM, &action, nullptr), 0);
   // Also handle SIGINT - when the user terminates the browser via Ctrl+C. If
   // the browser process is being debugged, GDB will catch the SIGINT first.
   action.sa_handler = SIGINTHandler;
-  CHECK_EQ(sigaction(SIGINT, &action, NULL), 0);
+  CHECK_EQ(sigaction(SIGINT, &action, nullptr), 0);
   // And SIGHUP, for when the terminal disappears. On shutdown, many Linux
   // distros send SIGHUP, SIGTERM, and then SIGKILL.
   action.sa_handler = SIGHUPHandler;
-  CHECK_EQ(sigaction(SIGHUP, &action, NULL), 0);
+  CHECK_EQ(sigaction(SIGHUP, &action, nullptr), 0);
 }
 
 }  // namespace atom
diff --git a/atom/browser/net/asar/url_request_asar_job.cc b/atom/browser/net/asar/url_request_asar_job.cc
index 39e55a35cbce..9bcdfc6ff78b 100644
--- a/atom/browser/net/asar/url_request_asar_job.cc
+++ b/atom/browser/net/asar/url_request_asar_job.cc
@@ -183,7 +183,7 @@ bool URLRequestAsarJob::IsRedirectResponse(GURL* location,
 net::Filter* URLRequestAsarJob::SetupFilter() const {
   // Bug 9936 - .svgz files needs to be decompressed.
   return base::LowerCaseEqualsASCII(file_path_.Extension(), ".svgz")
-      ? net::Filter::GZipFactory() : NULL;
+      ? net::Filter::GZipFactory() : nullptr;
 }
 
 bool URLRequestAsarJob::GetMimeType(std::string* mime_type) const {
@@ -338,7 +338,7 @@ void URLRequestAsarJob::DidRead(scoped_refptr<net::IOBuffer> buf, int result) {
     DCHECK_GE(remaining_bytes_, 0);
   }
 
-  buf = NULL;
+  buf = nullptr;
 
   ReadRawDataComplete(result);
 }
diff --git a/atom/browser/relauncher_mac.cc b/atom/browser/relauncher_mac.cc
index ef26f8441df6..ac4c874c560d 100644
--- a/atom/browser/relauncher_mac.cc
+++ b/atom/browser/relauncher_mac.cc
@@ -43,7 +43,7 @@ void RelauncherSynchronizeWithParent() {
 
   struct kevent change = { 0 };
   EV_SET(&change, parent_pid, EVFILT_PROC, EV_ADD, NOTE_EXIT, 0, NULL);
-  if (kevent(kq.get(), &change, 1, NULL, 0, NULL) == -1) {
+  if (kevent(kq.get(), &change, 1, nullptr, 0, nullptr) == -1) {
     PLOG(ERROR) << "kevent (add)";
     return;
   }
@@ -58,7 +58,7 @@ void RelauncherSynchronizeWithParent() {
   // write above to complete. The parent process is now free to exit. Wait for
   // that to happen.
   struct kevent event;
-  int events = kevent(kq.get(), NULL, 0, &event, 1, NULL);
+  int events = kevent(kq.get(), nullptr, 0, &event, 1, nullptr);
   if (events != 1) {
     if (events < 0) {
       PLOG(ERROR) << "kevent (monitor)";
diff --git a/atom/browser/window_list.cc b/atom/browser/window_list.cc
index b3bec5d08c1c..537499022eaf 100644
--- a/atom/browser/window_list.cc
+++ b/atom/browser/window_list.cc
@@ -17,7 +17,7 @@ base::LazyInstance<base::ObserverList<WindowListObserver>>::Leaky
     WindowList::observers_ = LAZY_INSTANCE_INITIALIZER;
 
 // static
-WindowList* WindowList::instance_ = NULL;
+WindowList* WindowList::instance_ = nullptr;
 
 // static
 WindowList* WindowList::GetInstance() {
diff --git a/atom/common/api/atom_bindings.cc b/atom/common/api/atom_bindings.cc
index 599fc6749890..b5a51ad507e4 100644
--- a/atom/common/api/atom_bindings.cc
+++ b/atom/common/api/atom_bindings.cc
@@ -25,7 +25,7 @@ namespace {
 struct DummyClass { bool crash; };
 
 void Crash() {
-  static_cast<DummyClass*>(NULL)->crash = true;
+  static_cast<DummyClass*>(nullptr)->crash = true;
 }
 
 void Hang() {
diff --git a/atom/common/asar/archive.cc b/atom/common/asar/archive.cc
index c2306c3c8f38..e622effe5d3d 100644
--- a/atom/common/asar/archive.cc
+++ b/atom/common/asar/archive.cc
@@ -41,7 +41,7 @@ bool GetFilesNode(const base::DictionaryValue* root,
   // Test for symbol linked directory.
   std::string link;
   if (dir->GetStringWithoutPathExpansion("link", &link)) {
-    const base::DictionaryValue* linked_node = NULL;
+    const base::DictionaryValue* linked_node = nullptr;
     if (!GetNodeFromPath(link, root, &linked_node))
       return false;
     dir = linked_node;
@@ -60,7 +60,7 @@ bool GetChildNode(const base::DictionaryValue* root,
     return true;
   }
 
-  const base::DictionaryValue* files = NULL;
+  const base::DictionaryValue* files = nullptr;
   return GetFilesNode(root, dir, &files) &&
          files->GetDictionaryWithoutPathExpansion(name, out);
 }
@@ -78,7 +78,7 @@ bool GetNodeFromPath(std::string path,
   for (size_t delimiter_position = path.find_first_of(kSeparators);
        delimiter_position != std::string::npos;
        delimiter_position = path.find_first_of(kSeparators)) {
-    const base::DictionaryValue* child = NULL;
+    const base::DictionaryValue* child = nullptr;
     if (!GetChildNode(root, path.substr(0, delimiter_position), dir, &child))
       return false;
 
diff --git a/atom/common/native_mate_converters/v8_value_converter.cc b/atom/common/native_mate_converters/v8_value_converter.cc
index ff96b727e02a..a4ecc3ded97f 100644
--- a/atom/common/native_mate_converters/v8_value_converter.cc
+++ b/atom/common/native_mate_converters/v8_value_converter.cc
@@ -162,7 +162,7 @@ v8::Local<v8::Value> V8ValueConverter::ToV8Array(
   v8::Local<v8::Array> result(v8::Array::New(isolate, val->GetSize()));
 
   for (size_t i = 0; i < val->GetSize(); ++i) {
-    const base::Value* child = NULL;
+    const base::Value* child = nullptr;
     CHECK(val->Get(i, &child));
 
     v8::Local<v8::Value> child_v8 = ToV8ValueImpl(isolate, child);
@@ -214,7 +214,7 @@ base::Value* V8ValueConverter::FromV8ValueImpl(
 
   FromV8ValueState::Level state_level(state);
   if (state->HasReachedMaxRecursionDepth())
-    return NULL;
+    return nullptr;
 
   if (val->IsNull())
     return base::Value::CreateNullValue().release();
@@ -235,7 +235,7 @@ base::Value* V8ValueConverter::FromV8ValueImpl(
 
   if (val->IsUndefined())
     // JSON.stringify ignores undefined.
-    return NULL;
+    return nullptr;
 
   if (val->IsDate()) {
     v8::Date* date = v8::Date::Cast(*val);
@@ -265,7 +265,7 @@ base::Value* V8ValueConverter::FromV8ValueImpl(
   if (val->IsFunction()) {
     if (!function_allowed_)
       // JSON.stringify refuses to convert function(){}.
-      return NULL;
+      return nullptr;
     return FromV8Object(val->ToObject(), state, isolate);
   }
 
@@ -278,7 +278,7 @@ base::Value* V8ValueConverter::FromV8ValueImpl(
   }
 
   LOG(ERROR) << "Unexpected v8 value type encountered.";
-  return NULL;
+  return nullptr;
 }
 
 base::Value* V8ValueConverter::FromV8Array(
diff --git a/atom/common/node_bindings_mac.cc b/atom/common/node_bindings_mac.cc
index 9e61d27f496b..6be1226ae314 100644
--- a/atom/common/node_bindings_mac.cc
+++ b/atom/common/node_bindings_mac.cc
@@ -54,7 +54,7 @@ void NodeBindingsMac::PollEvents() {
   // Wait for new libuv events.
   int r;
   do {
-    r = select(fd + 1, &readset, NULL, NULL, timeout == -1 ? NULL : &tv);
+    r = select(fd + 1, &readset, nullptr, nullptr, timeout == -1 ? nullptr : &tv);
   } while (r == -1 && errno == EINTR);
 }
 
diff --git a/atom/renderer/api/atom_api_renderer_ipc.cc b/atom/renderer/api/atom_api_renderer_ipc.cc
index a82562f93614..49f917292bb2 100644
--- a/atom/renderer/api/atom_api_renderer_ipc.cc
+++ b/atom/renderer/api/atom_api_renderer_ipc.cc
@@ -20,11 +20,11 @@ namespace {
 RenderView* GetCurrentRenderView() {
   WebLocalFrame* frame = WebLocalFrame::frameForCurrentContext();
   if (!frame)
-    return NULL;
+    return nullptr;
 
   WebView* view = frame->view();
   if (!view)
-    return NULL;  // can happen during closing.
+    return nullptr;  // can happen during closing.
 
   return RenderView::FromWebView(view);
 }
@@ -33,7 +33,7 @@ void Send(mate::Arguments* args,
           const base::string16& channel,
           const base::ListValue& arguments) {
   RenderView* render_view = GetCurrentRenderView();
-  if (render_view == NULL)
+  if (render_view == nullptr)
     return;
 
   bool success = render_view->Send(new AtomViewHostMsg_Message(
@@ -49,7 +49,7 @@ base::string16 SendSync(mate::Arguments* args,
   base::string16 json;
 
   RenderView* render_view = GetCurrentRenderView();
-  if (render_view == NULL)
+  if (render_view == nullptr)
     return json;
 
   IPC::SyncMessage* message = new AtomViewHostMsg_Message_Sync(
diff --git a/chromium_src/chrome/browser/browser_process.cc b/chromium_src/chrome/browser/browser_process.cc
index 2c07333210ea..34e79812bf21 100644
--- a/chromium_src/chrome/browser/browser_process.cc
+++ b/chromium_src/chrome/browser/browser_process.cc
@@ -7,7 +7,7 @@
 #include "chrome/browser/printing/print_job_manager.h"
 #include "ui/base/l10n/l10n_util.h"
 
-BrowserProcess* g_browser_process = NULL;
+BrowserProcess* g_browser_process = nullptr;
 
 BrowserProcess::BrowserProcess() {
   g_browser_process = this;
@@ -16,7 +16,7 @@ BrowserProcess::BrowserProcess() {
 }
 
 BrowserProcess::~BrowserProcess() {
-  g_browser_process = NULL;
+  g_browser_process = nullptr;
 }
 
 std::string BrowserProcess::GetApplicationLocale() {
diff --git a/chromium_src/chrome/browser/media/native_desktop_media_list.cc b/chromium_src/chrome/browser/media/native_desktop_media_list.cc
index a524dfcf38cb..410a9430a335 100644
--- a/chromium_src/chrome/browser/media/native_desktop_media_list.cc
+++ b/chromium_src/chrome/browser/media/native_desktop_media_list.cc
@@ -220,7 +220,7 @@ void NativeDesktopMediaList::Worker::Refresh(
 
 webrtc::SharedMemory* NativeDesktopMediaList::Worker::CreateSharedMemory(
     size_t size) {
-  return NULL;
+  return nullptr;
 }
 
 void NativeDesktopMediaList::Worker::OnCaptureCompleted(
@@ -236,7 +236,7 @@ NativeDesktopMediaList::NativeDesktopMediaList(
       update_period_(base::TimeDelta::FromMilliseconds(kDefaultUpdatePeriod)),
       thumbnail_size_(100, 100),
       view_dialog_id_(-1),
-      observer_(NULL),
+      observer_(nullptr),
       weak_factory_(this) {
   base::SequencedWorkerPool* worker_pool = BrowserThread::GetBlockingPool();
   capture_task_runner_ = worker_pool->GetSequencedTaskRunner(
diff --git a/chromium_src/chrome/browser/printing/print_job.cc b/chromium_src/chrome/browser/printing/print_job.cc
index 87971055e68f..0d4ad0d43893 100644
--- a/chromium_src/chrome/browser/printing/print_job.cc
+++ b/chromium_src/chrome/browser/printing/print_job.cc
@@ -38,7 +38,7 @@ void HoldRefCallback(const scoped_refptr<printing::PrintJobWorkerOwner>& owner,
 namespace printing {
 
 PrintJob::PrintJob()
-    : source_(NULL),
+    : source_(nullptr),
       worker_(),
       settings_(),
       is_job_pending_(false),
@@ -106,7 +106,7 @@ void PrintJob::GetSettingsDone(const PrintSettings& new_settings,
 
 PrintJobWorker* PrintJob::DetachWorker(PrintJobWorkerOwner* new_owner) {
   NOTREACHED();
-  return NULL;
+  return nullptr;
 }
 
 const PrintSettings& PrintJob::settings() const {
@@ -139,7 +139,7 @@ void PrintJob::StartPrinting() {
 
   // Tell everyone!
   scoped_refptr<JobEventDetails> details(
-      new JobEventDetails(JobEventDetails::NEW_DOC, document_.get(), NULL));
+      new JobEventDetails(JobEventDetails::NEW_DOC, document_.get(), nullptr));
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_PRINT_JOB_EVENT,
       content::Source<PrintJob>(this),
@@ -163,7 +163,7 @@ void PrintJob::Stop() {
     ControlledWorkerShutdown();
   } else {
     // Flush the cached document.
-    UpdatePrintedDocument(NULL);
+    UpdatePrintedDocument(nullptr);
   }
 }
 
@@ -183,7 +183,7 @@ void PrintJob::Cancel() {
   }
   // Make sure a Cancel() is broadcast.
   scoped_refptr<JobEventDetails> details(
-      new JobEventDetails(JobEventDetails::FAILED, NULL, NULL));
+      new JobEventDetails(JobEventDetails::FAILED, nullptr, nullptr));
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_PRINT_JOB_EVENT,
       content::Source<PrintJob>(this),
@@ -207,7 +207,7 @@ bool PrintJob::FlushJob(base::TimeDelta timeout) {
 }
 
 void PrintJob::DisconnectSource() {
-  source_ = NULL;
+  source_ = nullptr;
   if (document_.get())
     document_->DisconnectSource();
 }
@@ -388,7 +388,7 @@ void PrintJob::OnDocumentDone() {
   Stop();
 
   scoped_refptr<JobEventDetails> details(
-      new JobEventDetails(JobEventDetails::JOB_DONE, document_.get(), NULL));
+      new JobEventDetails(JobEventDetails::JOB_DONE, document_.get(), nullptr));
   content::NotificationService::current()->Notify(
       chrome::NOTIFICATION_PRINT_JOB_EVENT,
       content::Source<PrintJob>(this),
@@ -434,7 +434,7 @@ void PrintJob::ControlledWorkerShutdown() {
 
   is_job_pending_ = false;
   registrar_.RemoveAll();
-  UpdatePrintedDocument(NULL);
+  UpdatePrintedDocument(nullptr);
 }
 
 void PrintJob::HoldUntilStopIsCalled() {
diff --git a/chromium_src/chrome/browser/printing/print_job_manager.cc b/chromium_src/chrome/browser/printing/print_job_manager.cc
index ec08a9892335..a2e4fc1a718b 100644
--- a/chromium_src/chrome/browser/printing/print_job_manager.cc
+++ b/chromium_src/chrome/browser/printing/print_job_manager.cc
@@ -41,7 +41,7 @@ scoped_refptr<PrinterQuery> PrintQueriesQueue::PopPrinterQuery(
       return current_query;
     }
   }
-  return NULL;
+  return nullptr;
 }
 
 scoped_refptr<PrinterQuery> PrintQueriesQueue::CreatePrinterQuery(
@@ -90,7 +90,7 @@ void PrintJobManager::Shutdown() {
   StopJobs(true);
   if (queue_.get())
     queue_->Shutdown();
-  queue_ = NULL;
+  queue_ = nullptr;
 }
 
 void PrintJobManager::StopJobs(bool wait_for_finish) {
diff --git a/chromium_src/chrome/browser/printing/print_job_worker.cc b/chromium_src/chrome/browser/printing/print_job_worker.cc
index 7a88a8570c42..ad9bdf45bdb8 100644
--- a/chromium_src/chrome/browser/printing/print_job_worker.cc
+++ b/chromium_src/chrome/browser/printing/print_job_worker.cc
@@ -62,9 +62,9 @@ gfx::NativeView PrintingContextDelegate::GetParentView() {
   content::RenderViewHost* view =
       content::RenderViewHost::FromID(render_process_id_, render_view_id_);
   if (!view)
-    return NULL;
+    return nullptr;
   content::WebContents* wc = content::WebContents::FromRenderViewHost(view);
-  return wc ? wc->GetNativeView() : NULL;
+  return wc ? wc->GetNativeView() : nullptr;
 }
 
 std::string PrintingContextDelegate::GetAppLocale() {
@@ -343,7 +343,7 @@ void PrintJobWorker::OnDocumentDone() {
                               base::RetainedRef(document_), nullptr));
 
   // Makes sure the variables are reinitialized.
-  document_ = NULL;
+  document_ = nullptr;
 }
 
 void PrintJobWorker::SpoolPage(PrintedPage* page) {
@@ -397,7 +397,7 @@ void PrintJobWorker::OnFailure() {
   Cancel();
 
   // Makes sure the variables are reinitialized.
-  document_ = NULL;
+  document_ = nullptr;
   page_number_ = PageNumber::npos();
 }
 
diff --git a/chromium_src/chrome/browser/printing/print_view_manager_base.cc b/chromium_src/chrome/browser/printing/print_view_manager_base.cc
index 2bbafdd8e55a..7de8ae56fd72 100644
--- a/chromium_src/chrome/browser/printing/print_view_manager_base.cc
+++ b/chromium_src/chrome/browser/printing/print_view_manager_base.cc
@@ -394,7 +394,7 @@ void PrintViewManagerBase::ReleasePrintJob() {
                     content::Source<PrintJob>(print_job_.get()));
   print_job_->DisconnectSource();
   // Don't close the worker thread.
-  print_job_ = NULL;
+  print_job_ = nullptr;
 }
 
 bool PrintViewManagerBase::RunInnerMessageLoop() {
diff --git a/chromium_src/chrome/browser/printing/printer_query.cc b/chromium_src/chrome/browser/printing/printer_query.cc
index 72e2b85f635c..d36d51a9f890 100644
--- a/chromium_src/chrome/browser/printing/printer_query.cc
+++ b/chromium_src/chrome/browser/printing/printer_query.cc
@@ -122,7 +122,7 @@ bool PrinterQuery::is_callback_pending() const {
 }
 
 bool PrinterQuery::is_valid() const {
-  return worker_.get() != NULL;
+  return worker_.get() != nullptr;
 }
 
 }  // namespace printing
diff --git a/chromium_src/chrome/browser/printing/printing_message_filter.cc b/chromium_src/chrome/browser/printing/printing_message_filter.cc
index 819c6af5b020..31a7cf535a66 100644
--- a/chromium_src/chrome/browser/printing/printing_message_filter.cc
+++ b/chromium_src/chrome/browser/printing/printing_message_filter.cc
@@ -246,7 +246,7 @@ content::WebContents* PrintingMessageFilter::GetWebContentsForRenderView(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   content::RenderViewHost* view = content::RenderViewHost::FromID(
       render_process_id_, render_view_id);
-  return view ? content::WebContents::FromRenderViewHost(view) : NULL;
+  return view ? content::WebContents::FromRenderViewHost(view) : nullptr;
 }
 
 void PrintingMessageFilter::OnGetDefaultPrintSettings(IPC::Message* reply_msg) {
diff --git a/chromium_src/chrome/browser/process_singleton_posix.cc b/chromium_src/chrome/browser/process_singleton_posix.cc
index 5742b3585205..cb624fec5ae3 100644
--- a/chromium_src/chrome/browser/process_singleton_posix.cc
+++ b/chromium_src/chrome/browser/process_singleton_posix.cc
@@ -171,7 +171,7 @@ int WaitSocketForRead(int fd, const base::TimeDelta& timeout) {
   FD_ZERO(&read_fds);
   FD_SET(fd, &read_fds);
 
-  return HANDLE_EINTR(select(fd + 1, &read_fds, NULL, NULL, &tv));
+  return HANDLE_EINTR(select(fd + 1, &read_fds, nullptr, nullptr, &tv));
 }
 
 // Read a message from a socket fd, with an optional timeout.
diff --git a/chromium_src/chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.cc b/chromium_src/chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.cc
index 10c07906af9b..bf4d0f02a66a 100644
--- a/chromium_src/chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.cc
+++ b/chromium_src/chrome/browser/renderer_host/pepper/pepper_isolated_file_system_message_filter.cc
@@ -26,7 +26,7 @@ PepperIsolatedFileSystemMessageFilter::Create(PP_Instance instance,
   int unused_render_frame_id;
   if (!host->GetRenderFrameIDsForInstance(
           instance, &render_process_id, &unused_render_frame_id)) {
-    return NULL;
+    return nullptr;
   }
   return new PepperIsolatedFileSystemMessageFilter(
       render_process_id,
diff --git a/chromium_src/chrome/browser/speech/tts_controller_impl.cc b/chromium_src/chrome/browser/speech/tts_controller_impl.cc
index 610ce1656759..3147e8550815 100644
--- a/chromium_src/chrome/browser/speech/tts_controller_impl.cc
+++ b/chromium_src/chrome/browser/speech/tts_controller_impl.cc
@@ -115,10 +115,10 @@ TtsControllerImpl* TtsControllerImpl::GetInstance() {
 }
 
 TtsControllerImpl::TtsControllerImpl()
-    : current_utterance_(NULL),
+    : current_utterance_(nullptr),
       paused_(false),
-      platform_impl_(NULL),
-      tts_engine_delegate_(NULL) {
+      platform_impl_(nullptr),
+      tts_engine_delegate_(nullptr) {
 }
 
 TtsControllerImpl::~TtsControllerImpl() {
@@ -206,7 +206,7 @@ void TtsControllerImpl::SpeakNow(Utterance* utterance) {
     if (!sends_end_event) {
       utterance->Finish();
       delete utterance;
-      current_utterance_ = NULL;
+      current_utterance_ = nullptr;
       SpeakNextUtterance();
     }
 #endif
@@ -222,7 +222,7 @@ void TtsControllerImpl::SpeakNow(Utterance* utterance) {
         voice,
         utterance->continuous_parameters());
     if (!success)
-      current_utterance_ = NULL;
+      current_utterance_ = nullptr;
 
     // If the native voice wasn't able to process this speech, see if
     // the browser has built-in TTS that isn't loaded yet.
@@ -323,7 +323,7 @@ void TtsControllerImpl::GetVoices(content::BrowserContext* browser_context,
 }
 
 bool TtsControllerImpl::IsSpeaking() {
-  return current_utterance_ != NULL || GetPlatformImpl()->IsSpeaking();
+  return current_utterance_ != nullptr || GetPlatformImpl()->IsSpeaking();
 }
 
 void TtsControllerImpl::FinishCurrentUtterance() {
@@ -332,7 +332,7 @@ void TtsControllerImpl::FinishCurrentUtterance() {
       current_utterance_->OnTtsEvent(TTS_EVENT_INTERRUPTED, kInvalidCharIndex,
                                      std::string());
     delete current_utterance_;
-    current_utterance_ = NULL;
+    current_utterance_ = nullptr;
   }
 }
 
diff --git a/chromium_src/chrome/renderer/pepper/pepper_flash_menu_host.cc b/chromium_src/chrome/renderer/pepper/pepper_flash_menu_host.cc
index 3b7a438f7220..424b6ac6fdb7 100644
--- a/chromium_src/chrome/renderer/pepper/pepper_flash_menu_host.cc
+++ b/chromium_src/chrome/renderer/pepper/pepper_flash_menu_host.cc
@@ -195,7 +195,7 @@ void PepperFlashMenuHost::OnMenuClosed(int request_id) {
 void PepperFlashMenuHost::SendMenuReply(int32_t result, int action) {
   ppapi::host::ReplyMessageContext reply_context(
       ppapi::proxy::ResourceMessageReplyParams(pp_resource(), 0),
-      NULL,
+      nullptr,
       MSG_ROUTING_NONE);
   reply_context.params.set_result(result);
   host()->SendReply(reply_context, PpapiPluginMsg_FlashMenu_ShowReply(action));
diff --git a/chromium_src/chrome/renderer/pepper/pepper_flash_renderer_host.cc b/chromium_src/chrome/renderer/pepper/pepper_flash_renderer_host.cc
index 59046b328bfe..6606d736c042 100644
--- a/chromium_src/chrome/renderer/pepper/pepper_flash_renderer_host.cc
+++ b/chromium_src/chrome/renderer/pepper/pepper_flash_renderer_host.cc
@@ -115,7 +115,7 @@ bool IsSimpleHeader(const std::string& lower_case_header_name,
                                     &lower_case_mime_type,
                                     &lower_case_charset,
                                     &had_charset,
-                                    NULL);
+                                    nullptr);
     return lower_case_mime_type == "application/x-www-form-urlencoded" ||
            lower_case_mime_type == "multipart/form-data" ||
            lower_case_mime_type == "text/plain";
diff --git a/chromium_src/chrome/renderer/printing/print_web_view_helper.cc b/chromium_src/chrome/renderer/printing/print_web_view_helper.cc
index 7ff3471f953a..0ab64248cf87 100644
--- a/chromium_src/chrome/renderer/printing/print_web_view_helper.cc
+++ b/chromium_src/chrome/renderer/printing/print_web_view_helper.cc
@@ -110,8 +110,8 @@ PrintMsg_Print_Params GetCssPrintParams(
 
   // Invalid page size and/or margins. We just use the default setting.
   if (new_content_width < 1 || new_content_height < 1) {
-    CHECK(frame != NULL);
-    page_css_params = GetCssPrintParams(NULL, page_index, page_params);
+    CHECK(frame != nullptr);
+    page_css_params = GetCssPrintParams(nullptr, page_index, page_params);
     return page_css_params;
   }
 
@@ -254,7 +254,7 @@ void ComputeWebKitPrintParamsInDesiredDpi(
 
 blink::WebPlugin* GetPlugin(const blink::WebFrame* frame) {
   return frame->document().isPluginDocument() ?
-         frame->document().to<blink::WebPluginDocument>().plugin() : NULL;
+         frame->document().to<blink::WebPluginDocument>().plugin() : nullptr;
 }
 
 bool PrintingNodeOrPdfFrame(const blink::WebFrame* frame,
@@ -323,7 +323,7 @@ FrameReference::FrameReference(blink::WebLocalFrame* frame) {
 }
 
 FrameReference::FrameReference() {
-  Reset(NULL);
+  Reset(nullptr);
 }
 
 FrameReference::~FrameReference() {
@@ -334,20 +334,20 @@ void FrameReference::Reset(blink::WebLocalFrame* frame) {
     view_ = frame->view();
     frame_ = frame;
   } else {
-    view_ = NULL;
-    frame_ = NULL;
+    view_ = nullptr;
+    frame_ = nullptr;
   }
 }
 
 blink::WebLocalFrame* FrameReference::GetFrame() {
-  if (view_ == NULL || frame_ == NULL)
-    return NULL;
-  for (blink::WebFrame* frame = view_->mainFrame(); frame != NULL;
+  if (view_ == nullptr || frame_ == nullptr)
+    return nullptr;
+  for (blink::WebFrame* frame = view_->mainFrame(); frame != nullptr;
            frame = frame->traverseNext(false)) {
     if (frame == frame_)
       return frame_;
   }
-  return NULL;
+  return nullptr;
 }
 
 blink::WebView* FrameReference::view() {
@@ -477,7 +477,7 @@ PrepareFrameAndViewForPrint::PrepareFrameAndViewForPrint(
     frame->printBegin(web_print_params_, node_to_print_);
     print_params = CalculatePrintParamsForCss(frame, 0, print_params,
                                               ignore_css_margins, fit_to_page,
-                                              NULL);
+                                              nullptr);
     frame->printEnd();
   }
   ComputeWebKitPrintParamsInDesiredDpi(print_params, &web_print_params_);
@@ -623,7 +623,7 @@ void PrepareFrameAndViewForPrint::FinishPrinting() {
       web_view->close();
     }
   }
-  frame_.Reset(NULL);
+  frame_.Reset(nullptr);
   on_ready_.Reset();
 }
 
diff --git a/chromium_src/chrome/renderer/spellchecker/spellcheck_worditerator.cc b/chromium_src/chrome/renderer/spellchecker/spellcheck_worditerator.cc
index 46465f4dfd4a..4b1b03956272 100644
--- a/chromium_src/chrome/renderer/spellchecker/spellcheck_worditerator.cc
+++ b/chromium_src/chrome/renderer/spellchecker/spellcheck_worditerator.cc
@@ -301,8 +301,8 @@ bool SpellcheckCharAttribute::OutputDefault(UChar c,
 // SpellcheckWordIterator implementation:
 
 SpellcheckWordIterator::SpellcheckWordIterator()
-    : text_(NULL),
-      attribute_(NULL),
+    : text_(nullptr),
+      attribute_(nullptr),
       iterator_() {
 }
 
diff --git a/chromium_src/extensions/common/url_pattern.cc b/chromium_src/extensions/common/url_pattern.cc
index 4303689fe81c..b963626b98f2 100644
--- a/chromium_src/extensions/common/url_pattern.cc
+++ b/chromium_src/extensions/common/url_pattern.cc
@@ -346,7 +346,7 @@ bool URLPattern::SetPort(const std::string& port) {
 
 bool URLPattern::MatchesURL(const GURL& test) const {
   const GURL* test_url = &test;
-  bool has_inner_url = test.inner_url() != NULL;
+  bool has_inner_url = test.inner_url() != nullptr;
 
   if (has_inner_url) {
     if (!test.SchemeIsFileSystem())
@@ -370,7 +370,7 @@ bool URLPattern::MatchesURL(const GURL& test) const {
 
 bool URLPattern::MatchesSecurityOrigin(const GURL& test) const {
   const GURL* test_url = &test;
-  bool has_inner_url = test.inner_url() != NULL;
+  bool has_inner_url = test.inner_url() != nullptr;
 
   if (has_inner_url) {
     if (!test.SchemeIsFileSystem())
diff --git a/chromium_src/net/test/embedded_test_server/stream_listen_socket.cc b/chromium_src/net/test/embedded_test_server/stream_listen_socket.cc
index 2514c636cbee..0b93c7a93697 100644
--- a/chromium_src/net/test/embedded_test_server/stream_listen_socket.cc
+++ b/chromium_src/net/test/embedded_test_server/stream_listen_socket.cc
@@ -123,7 +123,7 @@ int StreamListenSocket::GetPeerAddress(IPEndPoint* address) const {
 }
 
 SocketDescriptor StreamListenSocket::AcceptSocket() {
-  SocketDescriptor conn = HANDLE_EINTR(accept(socket_, NULL, NULL));
+  SocketDescriptor conn = HANDLE_EINTR(accept(socket_, nullptr, nullptr));
   if (conn == kInvalidSocket)
     LOG(ERROR) << "Error accepting connection.";
   else