[Experimental - DO NOT LAND] Use border-image for MD History shadows.

chrome/browser/ui/webui/md_history_ui.cc

 // Copyright 2015 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 "chrome/browser/ui/webui/md_history_ui.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "build/build_config.h"
@@ skipping 116 matching lines @@
   source->AddBoolean("isGuestSession", profile->IsGuestSession());
 
   SigninManagerBase* signin_manager =
       SigninManagerFactory::GetForProfile(profile);
   bool is_authenticated = signin_manager != nullptr &&
       signin_manager->IsAuthenticated();
   source->AddBoolean("isUserSignedIn", is_authenticated);
 
   source->AddResourcePath("constants.html", IDR_MD_HISTORY_CONSTANTS_HTML);
   source->AddResourcePath("constants.js", IDR_MD_HISTORY_CONSTANTS_JS);
+  source->AddResourcePath("images/100/shadow_border.png",
+                          IDR_MD_HISTORY_IMAGES_100_SHADOW_BORDER_PNG);
   source->AddResourcePath("images/100/sign_in_promo.png",
                           IDR_MD_HISTORY_IMAGES_100_SIGN_IN_PROMO_PNG);
   source->AddResourcePath("images/200/sign_in_promo.png",
                           IDR_MD_HISTORY_IMAGES_200_SIGN_IN_PROMO_PNG);
   source->AddResourcePath("history.js", IDR_MD_HISTORY_HISTORY_JS);
 
 #if BUILDFLAG(USE_VULCANIZE)
   source->AddResourcePath("app.html",
                           IDR_MD_HISTORY_APP_VULCANIZED_HTML);
   source->AddResourcePath("app.crisper.js",
@@ skipping 111 matching lines @@
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(prefs::kMdHistoryMenuPromoShown, false,
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }
 
 void MdHistoryUI::HandleMenuPromoShown(const base::ListValue* args) {
   Profile::FromWebUI(web_ui())->GetPrefs()->SetBoolean(
       prefs::kMdHistoryMenuPromoShown, true);
   data_source_->AddBoolean("showMenuPromo", false);
 }