Fix shelf layout when switching from left-aligned shelf to right-aligned shelf

ash/system/tray/system_tray.cc

Index: ash/system/tray/system_tray.cc
diff --git a/ash/system/tray/system_tray.cc b/ash/system/tray/system_tray.cc
index 35227cb0f4bc85a16dd6dff3989d8434143a9bf0..e5b56d1812ba31903bf368aeab4d50643328456e 100644
--- a/ash/system/tray/system_tray.cc
+++ b/ash/system/tray/system_tray.cc
@@ -149,12 +149,12 @@ SystemTray::~SystemTray() {
   }
 }
 
-void SystemTray::InitializeTrayItems(
-    SystemTrayDelegate* delegate,
-    WebNotificationTray* web_notification_tray) {
+void SystemTray::InitializeTrayItems(SystemTrayDelegate* delegate,
+                                     WebNotificationTray* web_notification_tray,
+                                     const gfx::Insets& insets) {
   DCHECK(web_notification_tray);
   web_notification_tray_ = web_notification_tray;
-  TrayBackgroundView::Initialize();
+  TrayBackgroundView::Initialize(insets);
   CreateItems(delegate);
 }
 
@@ -600,10 +600,11 @@ base::string16 SystemTray::GetAccessibleTimeString(
                                                     base::kKeepAmPm);
 }
 
-void SystemTray::SetShelfAlignment(ShelfAlignment alignment) {
+void SystemTray::SetShelfAlignment(ShelfAlignment alignment,
+                                   const gfx::Insets& insets) {
   if (alignment == shelf_alignment())
     return;
-  TrayBackgroundView::SetShelfAlignment(alignment);
+  TrayBackgroundView::SetShelfAlignment(alignment, insets);
   UpdateAfterShelfAlignmentChange(alignment);
   // Destroy any existing bubble so that it is rebuilt correctly.
   CloseSystemBubbleAndDeactivateSystemTray();