[Chrome OS MD] Draw a 1px separator between 2 tray items

ash/common/system/chromeos/ime_menu/ime_menu_tray.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/chromeos/ime_menu/ime_menu_tray.h"
 
 #include "ash/common/session/session_state_delegate.h"
+#include "ash/common/shelf/wm_shelf_observer.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/chromeos/ime_menu/ime_list_view.h"
 #include "ash/common/system/tray/system_tray_delegate.h"
 #include "ash/common/system/tray/system_tray_notifier.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_popup_header_button.h"
 #include "ash/common/system/tray/tray_utils.h"
 #include "ash/common/wm_lookup.h"
 #include "ash/common/wm_root_window_controller.h"
@@ skipping 112 matching lines @@
   TrayPopupHeaderButton* emoji_button_;
   TrayPopupHeaderButton* voice_button_;
   TrayPopupHeaderButton* handwriting_button_;
   TrayPopupHeaderButton* settings_button_;
 
   DISALLOW_COPY_AND_ASSIGN(ImeButtonsView);
 };
 
 }  // namespace
 
-ImeMenuTray::ImeMenuTray(WmShelf* wm_shelf)
-    : TrayBackgroundView(wm_shelf), label_(new ImeMenuLabel()) {
+ImeMenuTray::ImeMenuTray(WmShelf* wm_shelf, WmShelfObserver* wm_shelf_observer)
+    : TrayBackgroundView(wm_shelf, wm_shelf_observer),
+      label_(new ImeMenuLabel()) {
   SetupLabelForTray(label_);
   tray_container()->AddChildView(label_);
   SetContentsBackground();
   WmShell::Get()->system_tray_notifier()->AddIMEObserver(this);
 }
 
 ImeMenuTray::~ImeMenuTray() {
   WmShell::Get()->system_tray_notifier()->RemoveIMEObserver(this);
 }
 
@@ skipping 120 matching lines @@
   bubble_.reset(new ash::TrayBubbleWrapper(this, bubble_view));
   SetDrawBackgroundAsActive(true);
 }
 
 void ImeMenuTray::HideImeMenuBubble() {
   bubble_.reset();
   SetDrawBackgroundAsActive(false);
 }
 
 }  // namespace ash