mash: Introduce ShowWebDialogWithContainer for webui dialogs

chrome/browser/ui/ash/system_tray_delegate_chromeos.cc

Index: chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
index 77d9c12076246f7febc53007826713be2a0466c1..8dfda9900227ec4d2f6c367d63cd892ab2fad5b3 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
@@ -349,8 +349,9 @@ bool SystemTrayDelegateChromeOS::ShouldShowSettings() {
 }
 
 void SystemTrayDelegateChromeOS::ShowSetTimeDialog() {
-  // TODO(mash): Refactor out GetNativeWindow and move to SystemTrayClient.
-  SetTimeDialog::ShowDialog(GetNativeWindow());
+  // TODO(mash): Move to SystemTrayClient.
+  SetTimeDialog::ShowDialogInContainer(
+      SystemTrayClient::GetDialogParentContainerId());
 }
 
 void SystemTrayDelegateChromeOS::ShowEnterpriseInfo() {