ash: Use system tray mojo interface to show system update tray icon

ash/common/system/update/tray_update_unittest.cc

Index: ash/common/system/update/tray_update_unittest.cc
diff --git a/ash/common/system/update/tray_update_unittest.cc b/ash/common/system/update/tray_update_unittest.cc
index 1c6c796dbfaa3752e9b15abfa97b42957a32b0de..6aa8f1b4b02da9cad1e5140b34665fc602c3b57c 100644
--- a/ash/common/system/update/tray_update_unittest.cc
+++ b/ash/common/system/update/tray_update_unittest.cc
@@ -5,10 +5,10 @@
 #include "ash/common/system/update/tray_update.h"
 
 #include "ash/common/system/tray/system_tray.h"
-#include "ash/common/system/tray/system_tray_delegate.h"
-#include "ash/common/system/tray/system_tray_notifier.h"
+#include "ash/common/system/tray/system_tray_controller.h"
 #include "ash/common/test/ash_test.h"
 #include "ash/common/wm_shell.h"
+#include "ash/public/interfaces/update.mojom.h"
 
 namespace ash {
 
@@ -19,18 +19,12 @@ using TrayUpdateTest = AshTest;
 TEST_F(TrayUpdateTest, VisibilityAfterUpdate) {
   TrayUpdate* tray_update = GetPrimarySystemTray()->GetTrayUpdateForTesting();
 
-  // The system starts with no update pending.
-  UpdateInfo initial_info;
-  WmShell::Get()->system_tray_delegate()->GetSystemUpdateInfo(&initial_info);
-  EXPECT_FALSE(initial_info.update_required);
-
-  // When no update is pending, the item isn't visible.
+  // The system starts with no update pending, so the icon isn't visible.
   EXPECT_FALSE(tray_update->tray_view()->visible());
 
   // Simulate an update.
-  UpdateInfo info;
-  info.update_required = true;
-  WmShell::Get()->system_tray_notifier()->NotifyUpdateRecommended(info);
+  WmShell::Get()->system_tray_controller()->ShowUpdateIcon(

[James Cook, 2016/12/09 22:34:13]

I decided to test this at the SystemTrayController level instead of
SystemTrayNotifier because I think we should test as close as possible to the
exposed mojo interfaces.

[msw, 2016/12/09 23:41:51]

Acknowledged.

+      mojom::UpdateSeverity::LOW, false);
 
   // Tray item is now visible.
   EXPECT_TRUE(tray_update->tray_view()->visible());