Remove duplicate application cpp files in mojo/application.

mojo/services/tracing/main.cc

Index: mojo/services/tracing/main.cc
diff --git a/mojo/services/tracing/main.cc b/mojo/services/tracing/main.cc
index b0717ef46a3e3a67e7e64247464ad5e489624cb2..1810d1b27904b52ea9f5281936cca92e4045de77 100644
--- a/mojo/services/tracing/main.cc
+++ b/mojo/services/tracing/main.cc
@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "mojo/application/application_runner_chromium.h"
 #include "mojo/application/public/cpp/application_impl.h"
+#include "mojo/application/public/cpp/application_runner.h"
 #include "mojo/public/c/system/main.h"
 #include "mojo/services/tracing/tracing_app.h"
 
 MojoResult MojoMain(MojoHandle shell_handle) {
-  mojo::ApplicationRunnerChromium runner(new tracing::TracingApp);
+  mojo::ApplicationRunner runner(new tracing::TracingApp);
   return runner.Run(shell_handle);
 }