Remove non-MD code from TrayBackgroundView

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/accessibility_delegate.h"
 #include "ash/common/ash_constants.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/session/session_state_delegate.h"
@@ skipping 331 matching lines @@
     scroller()->ClipHeightTo(height_range.start(), height_range.end());
     ImeListView::Layout();
   }
 
   DISALLOW_COPY_AND_ASSIGN(ImeMenuListView);
 };
 
 }  // namespace
 
 ImeMenuTray::ImeMenuTray(WmShelf* wm_shelf)
-    : TrayBackgroundView(wm_shelf),
+    : TrayBackgroundView(wm_shelf, true),
       label_(new ImeMenuLabel()),
       show_keyboard_(false),
       force_show_keyboard_(false),
       should_block_shelf_auto_hide_(false),
       keyboard_suppressed_(false),
       show_bubble_after_keyboard_hidden_(false) {
-  if (MaterialDesignController::IsShelfMaterial()) {
+  if (MaterialDesignController::IsShelfMaterial())
     SetInkDropMode(InkDropMode::ON);
-    SetContentsBackground(false);
-  } else {
-    SetContentsBackground(true);
-  }
   SetupLabelForTray(label_);
   tray_container()->AddChildView(label_);
   SystemTrayNotifier* tray_notifier = WmShell::Get()->system_tray_notifier();
   tray_notifier->AddIMEObserver(this);
   tray_notifier->AddVirtualKeyboardObserver(this);
 }
 
 ImeMenuTray::~ImeMenuTray() {
   if (bubble_)
     bubble_->bubble_view()->reset_delegate();
@@ skipping 268 matching lines @@
   WmShell::Get()->system_tray_delegate()->GetCurrentIME(&current_ime_);
 
   // Updates the tray label based on the current input method.
   if (current_ime_.third_party)
     label_->SetText(current_ime_.short_name + base::UTF8ToUTF16("*"));
   else
     label_->SetText(current_ime_.short_name);
 }
 
 }  // namespace ash