ApplicationImpl cleanup, part 1:

mojo/application/public/cpp/lib/application_test_base.cc

Index: mojo/application/public/cpp/lib/application_test_base.cc
diff --git a/mojo/application/public/cpp/lib/application_test_base.cc b/mojo/application/public/cpp/lib/application_test_base.cc
index 3b4a30e48377f668b4f92c6480f9b37174b84ee3..8a9c1032ce82f06f621b93b0ebe75079e04100ee 100644
--- a/mojo/application/public/cpp/lib/application_test_base.cc
+++ b/mojo/application/public/cpp/lib/application_test_base.cc
@@ -5,6 +5,7 @@
 #include "mojo/application/public/cpp/application_test_base.h"
 
 #include "base/command_line.h"
+#include "base/message_loop/message_loop.h"
 #include "base/strings/utf_string_conversions.h"
 #include "mojo/application/public/cpp/application_impl.h"
 #include "mojo/application/public/interfaces/application.mojom.h"
@@ -126,8 +127,10 @@ void ApplicationTestBase::SetUp() {
   MOJO_CHECK(g_shell);
 
   // New applications are constructed for each test to avoid persisting state.
-  application_impl_ = new ApplicationImpl(GetApplicationDelegate(),
-                                          g_application_request.Pass());
+  application_impl_ =
+      new ApplicationImpl(GetApplicationDelegate(),
+                          g_application_request.Pass(),
+                          base::MessageLoop::QuitWhenIdleClosure());
 
   // Fake application initialization.
   application_impl_->Initialize(g_shell.Pass(), g_url);