mash: Rename browser_driver to app_driver.

mash/app_driver/main.cc

Index: mash/app_driver/main.cc
diff --git a/mash/session/main.cc b/mash/app_driver/main.cc
similarity index 76%
copy from mash/session/main.cc
copy to mash/app_driver/main.cc
index 53806c764e34b59a034911b1c487ce3fd66c360a..a528096e8149ca10f2d2a0d9f8500e242bb0168e 100644
--- a/mash/session/main.cc
+++ b/mash/app_driver/main.cc
@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "mash/session/session.h"
+#include "mash/app_driver/app_driver.h"
 #include "mojo/public/c/system/main.h"
 #include "services/shell/public/cpp/application_runner.h"
 
 MojoResult MojoMain(MojoHandle shell_handle) {
-  shell::ApplicationRunner runner(new mash::session::Session);
+  shell::ApplicationRunner runner(new mash::app_driver::AppDriver);
   return runner.Run(shell_handle);
 }