Add Content API around CertStore.

chrome/browser/certificate_viewer.cc

 // Copyright (c) 2010 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/certificate_viewer.h"
 
-#include "content/browser/cert_store.h"
+#include "content/public/browser/cert_store.h"
+#include "net/base/x509_certificate.h"
 
 void ShowCertificateViewerByID(gfx::NativeWindow parent, int cert_id) {
   scoped_refptr<net::X509Certificate> cert;
-  CertStore::GetInstance()->RetrieveCert(cert_id, &cert);
+  content::CertStore::GetInstance()->RetrieveCert(cert_id, &cert);
   if (!cert.get()) {
     // The certificate was not found. Could be that the renderer crashed before
     // we displayed the page info.
     return;
   }
   ShowCertificateViewer(parent, cert);
 }