Use app list item shadow for app list folders.

ui/app_list/cocoa/apps_grid_view_item.mm

 // Copyright 2013 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.
 
 #import "ui/app_list/cocoa/apps_grid_view_item.h"
 
 #include "base/mac/foundation_util.h"
 #include "base/mac/mac_util.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
@@ skipping 256 matching lines @@
 - (void)updateButtonImage {
   const gfx::Size iconSize = gfx::Size(kIconSize, kIconSize);
   gfx::ImageSkia icon = [self model]->icon();
   if (icon.size() != iconSize) {
     icon = gfx::ImageSkiaOperations::CreateResizedImage(
         icon, skia::ImageOperations::RESIZE_BEST, iconSize);
   }
   NSImage* buttonImage = gfx::NSImageFromImageSkiaWithColorSpace(
       icon, base::mac::GetSRGBColorSpace());
   [[self button] setImage:buttonImage];
-  [[[self button] cell] setHasShadow:[self model]->has_shadow()];
+  [[[self button] cell] setHasShadow:true];
 }
 
 - (void)setModel:(app_list::AppListItem*)itemModel {
   [trackingArea_.get() clearOwner];
   if (!itemModel) {
     observerBridge_.reset();
     return;
   }
 
   observerBridge_.reset(new app_list::ItemModelObserverBridge(self, itemModel));
@@ skipping 157 matching lines @@
 }
 
 // Workaround for http://crbug.com/324365: AppKit in Mavericks tries to call
 // - [NSButtonCell item] when inspecting accessibility. Without this, an
 // unrecognized selector exception is thrown inside AppKit, crashing Chrome.
 - (id)item {
   return nil;
 }
 
 @end