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 7c4c33f2ae70efd87104812477b16d145b577569..b348dfdaeea2cb99f3396545d6dec458f5d2d761 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
@@ -608,11 +608,6 @@ 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();