chromeos: Move ownership of system tray width from chrome to ash

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 cff502b8a3b6e44e067817a83058e9b26b06b148..7c1e46c36882bc5b669b9fd94821abec6a1e2cc7 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
@@ -609,11 +609,6 @@ bool SystemTrayDelegateChromeOS::GetSessionLengthLimit(
   return have_session_length_limit_;
 }
 
-int SystemTrayDelegateChromeOS::GetSystemTrayMenuWidth() {
-  return l10n_util::GetLocalizedContentsWidthInPixels(
-      IDS_SYSTEM_TRAY_MENU_BUBBLE_WIDTH_PIXELS);
-}
-
 void SystemTrayDelegateChromeOS::ActiveUserWasChanged() {
   SetProfile(ProfileManager::GetActiveUserProfile());
   GetSystemTrayNotifier()->NotifyUserUpdate();