ash: Make sure all the sub-popups retain the same height as the main popup.

ash/system/tray/system_tray_item.cc

Index: ash/system/tray/system_tray_item.cc
diff --git a/ash/system/tray/system_tray_item.cc b/ash/system/tray/system_tray_item.cc
index ed5cdd25e4b548836fdd9db1430c030397918afd..61ea10f528247980b67663161e583bf5605c9fe7 100644
--- a/ash/system/tray/system_tray_item.cc
+++ b/ash/system/tray/system_tray_item.cc
@@ -44,8 +44,14 @@ void SystemTrayItem::DestroyDetailedView() {
 void SystemTrayItem::DestroyNotificationView() {
 }
 
+void SystemTrayItem::TransitionDetailedView() {
+  Shell::GetInstance()->tray()->ShowDetailedView(this, 0, true,
+      BUBBLE_USE_EXISTING);
+}
+
 void SystemTrayItem::PopupDetailedView(int for_seconds, bool activate) {
-  Shell::GetInstance()->tray()->ShowDetailedView(this, for_seconds, activate);
+  Shell::GetInstance()->tray()->ShowDetailedView(this, for_seconds, activate,
+      BUBBLE_CREATE_NEW);
 }
 
 void SystemTrayItem::SetDetailedViewCloseDelay(int for_seconds) {