Show the "cannot proceed" text only when appropriate.

content/browser/ssl/ssl_policy.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 CONTENT_BROWSER_SSL_SSL_POLICY_H_
 #define CONTENT_BROWSER_SSL_SSL_POLICY_H_
 #pragma once
 
 #include <string>
 
@@ skipping 34 matching lines @@
                    WebContentsImpl* web_contents);
 
   SSLPolicyBackend* backend() const { return backend_; }
 
  private:
   // Callback that the user chose to accept or deny the certificate.
   void OnAllowCertificate(scoped_refptr<SSLCertErrorHandler> handler,
                           bool allow);
 
   // Helper method for derived classes handling certificate errors.
-  // If the error can be overridden by the user, show a blocking page that
-  // lets the user continue or cancel the request.
-  // For fatal certificate errors, show a blocking page that only lets the
-  // user cancel the request.
-  void OnCertErrorInternal(SSLCertErrorHandler* handler, bool overridable);
+  //
+  // |overridable| indicates whether or not the user could (assuming perfect
+  // knowledge) successfully override the error and still get the security
+  // guarantees of TLS. |strict_enforcement| indicates whether or not the
+  // site the user is trying to connect to has requested strict enforcement
+  // of certificate validation (e.g. with HTTP Strict-Transport-Security).
+  void OnCertErrorInternal(SSLCertErrorHandler* handler,
+                           bool overridable,
+                           bool strict_enforcement);
 
   // If the security style of |entry| has not been initialized, then initialize
   // it with the default style for its URL.
   void InitializeEntryIfNeeded(content::NavigationEntryImpl* entry);
 
   // Mark |origin| as having run insecure content in the process with ID |pid|.
   void OriginRanInsecureContent(const std::string& origin, int pid);
 
   // The backend we use to enact our decisions.
   SSLPolicyBackend* backend_;
 
   DISALLOW_COPY_AND_ASSIGN(SSLPolicy);
 };
 
 #endif  // CONTENT_BROWSER_SSL_SSL_POLICY_H_