Moves ToastManager from Shell to WmShell

ash/common/wm_shell.cc

Index: ash/common/wm_shell.cc
diff --git a/ash/common/wm_shell.cc b/ash/common/wm_shell.cc
index cf87b86c42e8e718a1189627417a3a9c159ab4ff..dba032c66fe0139de2d0e4e2ba8d3815e44e27a9 100644
--- a/ash/common/wm_shell.cc
+++ b/ash/common/wm_shell.cc
@@ -13,6 +13,7 @@
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/brightness_control_delegate.h"
 #include "ash/common/system/keyboard_brightness_control_delegate.h"
+#include "ash/common/system/toast/toast_manager.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
@@ -49,6 +50,7 @@ void WmShell::Initialize() {
   // instead of the WmShell constructor.
   accessibility_delegate_.reset(delegate_->CreateAccessibilityDelegate());
   media_delegate_.reset(delegate_->CreateMediaDelegate());
+  toast_manager_.reset(new ToastManager);
 }
 
 void WmShell::Shutdown() {
@@ -166,4 +168,8 @@ void WmShell::DeleteMruWindowTracker() {
   mru_window_tracker_.reset();
 }
 
+void WmShell::DeleteToastManager() {
+  toast_manager_.reset();
+}
+
 }  // namespace ash