Initialize the message center as part of the testing browser process

ash/test/ash_interactive_ui_test_base.cc

Index: ash/test/ash_interactive_ui_test_base.cc
diff --git a/ash/test/ash_interactive_ui_test_base.cc b/ash/test/ash_interactive_ui_test_base.cc
index 4b246c6c904b697e432db42954207bf3960c1659..93fe5451293ebf280a1224795e5172cf85c94ae3 100644
--- a/ash/test/ash_interactive_ui_test_base.cc
+++ b/ash/test/ash_interactive_ui_test_base.cc
@@ -9,6 +9,7 @@
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/ui_base_paths.h"
 #include "ui/gl/test/gl_surface_test_support.h"
+#include "ui/message_center/message_center.h"
 
 namespace ash {
 namespace test {
@@ -30,12 +31,13 @@ void AshInteractiveUITestBase::SetUp() {
   ResourceBundle::GetSharedInstance().AddDataPackFromPath(
       resources_pack_path, ui::SCALE_FACTOR_NONE);
   env_ = aura::Env::CreateInstance();
-
+  message_center::MessageCenter::Initialize();
   test::AshTestBase::SetUp();
 }
 
 void AshInteractiveUITestBase::TearDown() {
   test::AshTestBase::TearDown();
+  message_center::MessageCenter::Shutdown();
   env_.reset();
 }