Run clang-modernize -use-nullptr over src/extensions/.

extensions/browser/api/dns/dns_api.cc

Index: extensions/browser/api/dns/dns_api.cc
diff --git a/extensions/browser/api/dns/dns_api.cc b/extensions/browser/api/dns/dns_api.cc
index ae611239bd36e203c48a80093d25d556304f5b6a..a0fa8c9aa83e57d999fe7db3c6687144cc3fcf02 100644
--- a/extensions/browser/api/dns/dns_api.cc
+++ b/extensions/browser/api/dns/dns_api.cc
@@ -23,10 +23,11 @@ namespace Resolve = extensions::core_api::dns::Resolve;
 namespace extensions {
 
 DnsResolveFunction::DnsResolveFunction()
-    : resource_context_(NULL),
+    : resource_context_(nullptr),
       response_(false),
       request_handle_(new net::HostResolver::RequestHandle()),
-      addresses_(new net::AddressList) {}
+      addresses_(new net::AddressList) {
+}
 
 DnsResolveFunction::~DnsResolveFunction() {}