In dialogs & dialog-like bubbles, make the escape button just close the prompt.

chrome/browser/ui/views/ssl_client_certificate_selector.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_SSL_CLIENT_CERTIFICATE_SELECTOR_H_
 #define CHROME_BROWSER_UI_VIEWS_SSL_CLIENT_CERTIFICATE_SELECTOR_H_
 
 #include "base/macros.h"
 #include "chrome/browser/ssl/ssl_client_auth_observer.h"
 #include "chrome/browser/ssl/ssl_client_certificate_selector.h"
 #include "chrome/browser/ui/views/certificate_selector.h"
+#include "content/public/browser/web_contents_observer.h"
 
 // This header file exists only for testing.  Chrome should access the
 // certificate selector only through the cross-platform interface
 // chrome/browser/ssl_client_certificate_selector.h.
 
 namespace content {
 class WebContents;
 }
 
 namespace net {
 class SSLCertRequestInfo;
 class X509Certificate;
 }
 
 class SSLClientCertificateSelector : public chrome::CertificateSelector,
-                                     public SSLClientAuthObserver {
+                                     public SSLClientAuthObserver,
+                                     public content::WebContentsObserver {
  public:
   SSLClientCertificateSelector(
       content::WebContents* web_contents,
       const scoped_refptr<net::SSLCertRequestInfo>& cert_request_info,
       std::unique_ptr<content::ClientCertificateDelegate> delegate);
   ~SSLClientCertificateSelector() override;
 
   void Init();
 
   // SSLClientAuthObserver:
   void OnCertSelectedByNotification() override;
 
   // chrome::CertificateSelector:
-  bool Cancel() override;
+  void DeleteDelegate() override;
   bool Accept() override;
-  bool Close() override;
+
+  // content::WebContentsObserver:
+  void WebContentsDestroyed() override;
 
  private:
   // Callback after unlocking certificate slot.
   void Unlocked(net::X509Certificate* cert);
 
   DISALLOW_COPY_AND_ASSIGN(SSLClientCertificateSelector);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_SSL_CLIENT_CERTIFICATE_SELECTOR_H_