mash: Move TrayUpdate to //ash/common

ash/common/system/update/tray_update_unittest.cc

Index: ash/common/system/update/tray_update_unittest.cc
diff --git a/ash/system/tray_update_unittest.cc b/ash/common/system/update/tray_update_unittest.cc
similarity index 89%
rename from ash/system/tray_update_unittest.cc
rename to ash/common/system/update/tray_update_unittest.cc
index dbaa8ff9fd8e45dfc33b384656f9aa7ff678a413..edafe03cc7317b589138d8c9ccb3610686439e95 100644
--- a/ash/system/tray_update_unittest.cc
+++ b/ash/common/system/update/tray_update_unittest.cc
@@ -2,11 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/system/tray_update.h"
+#include "ash/common/system/update/tray_update.h"
 
 #include "ash/common/system/tray/wm_system_tray_notifier.h"
 #include "ash/common/wm_shell.h"
-#include "ash/shell.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/test_system_tray_delegate.h"
@@ -19,8 +18,7 @@ using TrayUpdateTest = test::AshTestBase;
 // Tests that the update icon becomes visible when an update becomes
 // available.
 TEST_F(TrayUpdateTest, VisibilityAfterUpdate) {
-  TrayUpdate* tray_update =
-      Shell::GetInstance()->GetPrimarySystemTray()->GetTrayUpdateForTesting();
+  TrayUpdate* tray_update = GetPrimarySystemTray()->GetTrayUpdateForTesting();

[James Cook, 2016/06/13 20:56:26]

AshTestBase::GetPrimarySystemTray() is a dodge around DEPS. I'd like to try to
avoid ash/shell.h from appearing anywhere in the DEPS files under //ash/common,
as I think it will tempt people to continue using it. However, quite a bit of
the tray tests will need to look up a SystemTray from somewhere, and it's going
to be a while before I can move that one. WDYT?

[msw, 2016/06/13 21:18:57]

Why not add a WmShell interface function that returns nullptr on mus for now,
and ash::Shell::instance()->GetPrimarySystemTray() for aura? I don't actually
have a strong opinion, this dodge seems fine as a temporary measure, and it's
probably okay to just delay moving the test files until we fix their deps.

[James Cook, 2016/06/13 21:57:19]

As discussed offline, I'd prefer not to introduce a
WmShell::GetPrimarySystemTray(), since I don't want to encourage people to get
the "primary" system tray. I'm also a little nervous about introducing getters
for classes that haven't moved to //ash/common yet, and that return nullptr only
on mus. I'd prefer to wait.

[msw, 2016/06/13 22:11:13]

Acknowledged.

 
   // The system starts with no update pending.
   test::TestSystemTrayDelegate* tray_delegate = GetSystemTrayDelegate();