shill: Replace NULL with nullptr.

BUG=None
TEST=`USE=wimax FEATURES=test emerge-$BOARD shill`

Change-Id: I30ab47ff32dcadad09ae7a2baf4d4123a6ef0d8e
Reviewed-on: https://chromium-review.googlesource.com/220657
Reviewed-by: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
diff --git a/dns_server_tester_unittest.cc b/dns_server_tester_unittest.cc
index 9c6eb3a..e68d660 100644
--- a/dns_server_tester_unittest.cc
+++ b/dns_server_tester_unittest.cc
@@ -48,11 +48,8 @@
 class DNSServerTesterTest : public Test {
  public:
   DNSServerTesterTest()
-      : device_info_(new NiceMock<MockDeviceInfo>(
-          &control_,
-          reinterpret_cast<EventDispatcher *>(NULL),
-          reinterpret_cast<Metrics *>(NULL),
-          reinterpret_cast<Manager *>(NULL))),
+      : device_info_(
+            new NiceMock<MockDeviceInfo>(&control_, nullptr, nullptr, nullptr)),
         connection_(new StrictMock<MockConnection>(device_info_.get())),
         interface_name_(kInterfaceName),
         dns_servers_(kDNSServers, kDNSServers + 2) {}