Remove calls to deprecated MessageLoop methods in content.

content/browser/devtools/site_per_process_devtools_browsertest.cc

Index: content/browser/devtools/site_per_process_devtools_browsertest.cc
diff --git a/content/browser/devtools/site_per_process_devtools_browsertest.cc b/content/browser/devtools/site_per_process_devtools_browsertest.cc
index 1cd0052fa6931bdfdaa44d5d89af0f58ac9d62da..315b87521761b59562f2019c2286a52386e54fb2 100644
--- a/content/browser/devtools/site_per_process_devtools_browsertest.cc
+++ b/content/browser/devtools/site_per_process_devtools_browsertest.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/run_loop.h"
 #include "build/build_config.h"
 #include "content/browser/frame_host/frame_tree.h"
 #include "content/browser/site_per_process_browsertest.h"
@@ -45,7 +46,7 @@ class TestClient: public DevToolsAgentHostClient {
 
   void WaitForReply() {
     waiting_for_reply_ = true;
-    base::MessageLoop::current()->Run();
+    base::RunLoop().Run();
   }
 
  private: