New Tab Page: chrome-search://local-ntp/ files should not be cachable

chrome/browser/search/local_ntp_source.h

 // 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.
 
 #ifndef CHROME_BROWSER_SEARCH_LOCAL_NTP_SOURCE_H_
 #define CHROME_BROWSER_SEARCH_LOCAL_NTP_SOURCE_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "content/public/browser/url_data_source.h"
 
 class Profile;
 
 // Serves HTML and resources for the local new tab page i.e.
 // chrome-search://local-ntp/local-ntp.html
 class LocalNtpSource : public content::URLDataSource {
  public:
   explicit LocalNtpSource(Profile* profile);
 
  private:
   ~LocalNtpSource() override;
 
   // Overridden from content::URLDataSource:
   std::string GetSource() const override;
   void StartDataRequest(
       const std::string& path,
       const content::ResourceRequestInfo::WebContentsGetter& wc_getter,
       const content::URLDataSource::GotDataCallback& callback) override;
   std::string GetMimeType(const std::string& path) const override;
+  bool AllowCaching() const override;
   bool ShouldServiceRequest(const net::URLRequest* request) const override;
   std::string GetContentSecurityPolicyChildSrc() const override;
 
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalNtpSource);
 };
 
 #endif  // CHROME_BROWSER_SEARCH_LOCAL_NTP_SOURCE_H_