Fix the MD Incognito NTP background color regression

chrome/browser/ui/webui/ntp/ntp_resource_cache.cc

 // Copyright 2012 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/ntp/ntp_resource_cache.h"
 
 #include <string>
 
 #include "base/feature_list.h"
 #include "base/memory/ref_counted_memory.h"
@@ skipping 481 matching lines @@
 void NTPResourceCache::CreateNewTabIncognitoCSS() {
   // TODO(estade): this returns a subtly incorrect theme provider because
   // |profile_| is actually not the incognito profile. See crbug.com/568388
   const ui::ThemeProvider& tp =
       ThemeService::GetThemeProviderForProfile(profile_);
 
   // Get our theme colors
   SkColor color_background =
       tp.HasCustomImage(IDR_THEME_NTP_BACKGROUND)
           ? GetThemeColor(tp, ThemeProperties::COLOR_NTP_BACKGROUND)
-          : SkColorSetRGB(0x32, 0x32, 0x32);
+          : ThemeProperties::GetDefaultColor(
+                ThemeProperties::COLOR_NTP_BACKGROUND, true /* incognito */);
 
   // Generate the replacements.
   ui::TemplateReplacements substitutions;
 
   // Cache-buster for background.
   substitutions["themeId"] =
       profile_->GetPrefs()->GetString(prefs::kCurrentThemeID);
 
   // Colors.
   substitutions["colorBackground"] =
@@ skipping 81 matching lines @@
   // Get our template.
   static const base::StringPiece new_tab_theme_css(
       ResourceBundle::GetSharedInstance().GetRawDataResource(
           IDR_NEW_TAB_4_THEME_CSS));
 
   // Create the string from our template and the replacements.
   std::string css_string =
       ui::ReplaceTemplateExpressions(new_tab_theme_css, substitutions);
   new_tab_css_ = base::RefCountedString::TakeString(&css_string);
 }