Remove calls to deprecated MessageLoop methods on Windows and Linux.

net/tools/net_watcher/net_watcher.cc

Index: net/tools/net_watcher/net_watcher.cc
diff --git a/net/tools/net_watcher/net_watcher.cc b/net/tools/net_watcher/net_watcher.cc
index b623954c6e6a497c92224c5b8af412125900c5da..61304e14a926349ea3ff249f65a51fe202395ba1 100644
--- a/net/tools/net_watcher/net_watcher.cc
+++ b/net/tools/net_watcher/net_watcher.cc
@@ -15,6 +15,7 @@
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/strings/string_split.h"
 #include "base/values.h"
 #include "build/build_config.h"
@@ -214,7 +215,7 @@ int main(int argc, char* argv[]) {
   LOG(INFO) << "Watching for network events...";
 
   // Start watching for events.
-  network_loop.Run();
+  base::RunLoop().Run();
 
   proxy_config_service->RemoveObserver(&net_watcher);