Remove calls to deprecated MessageLoop methods in net.

net/tools/gdig/gdig.cc

Index: net/tools/gdig/gdig.cc
diff --git a/net/tools/gdig/gdig.cc b/net/tools/gdig/gdig.cc
index f40f142d3e7fec384194c41bc21264ca45314127..f3d84e31b49a3bbd60f4b7160085c37134b4f0fe 100644
--- a/net/tools/gdig/gdig.cc
+++ b/net/tools/gdig/gdig.cc
@@ -15,6 +15,7 @@
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
@@ -274,7 +275,7 @@ GDig::Result GDig::Main(int argc, const char* argv[]) {
   result_ = RESULT_PENDING;
   Start();
   if (result_ == RESULT_PENDING)
-    base::MessageLoop::current()->Run();
+    base::RunLoop().Run();
 
   // Destroy it while MessageLoopForIO is alive.
   dns_config_service_.reset();