Add certificate error handling to devtools.

content/public/browser/web_contents_observer.cc

 // Copyright (c) 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 "content/public/browser/web_contents_observer.h"
 
 #include "content/browser/web_contents/web_contents_impl.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/render_view_host.h"
 
@@ skipping 54 matching lines @@
     return MSG_ROUTING_NONE;
 
   return web_contents_->GetRenderViewHost()->GetRoutingID();
 }
 
 void WebContentsObserver::ResetWebContents() {
   web_contents_->RemoveObserver(this);
   web_contents_ = nullptr;
 }
 
+bool WebContentsObserver::NotifyCertificateError(CertErrorCallback callback) {
+  return false;
+}
+
 }  // namespace content