Gather metrics classifying the cause of the TLS fallback.

net/socket/ssl_client_socket_nss.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 NET_SOCKET_SSL_CLIENT_SOCKET_NSS_H_
 #define NET_SOCKET_SSL_CLIENT_SOCKET_NSS_H_
 
 #include <certt.h>
 #include <keyt.h>
 #include <nspr.h>
@@ skipping 84 matching lines @@
 
   // Socket implementation.
   int Read(IOBuffer* buf,
            int buf_len,
            const CompletionCallback& callback) override;
   int Write(IOBuffer* buf,
             int buf_len,
             const CompletionCallback& callback) override;
   int SetReceiveBufferSize(int32 size) override;
   int SetSendBufferSize(int32 size) override;
+
+  // SSLClientSocket implementation.
   ChannelIDService* GetChannelIDService() const override;
+  SSLFailureState GetSSLFailureState() const override;
 
  protected:
   // SSLClientSocket implementation.
   scoped_refptr<X509Certificate> GetUnverifiedServerCertificateChain()
       const override;
 
  private:
   // Helper class to handle marshalling any NSS interaction to and from the
   // NSS and network task runners. Not every call needs to happen on the Core
   class Core;
@@ skipping 93 matching lines @@
   // Added the following code Debugging in release mode.
   mutable base::Lock lock_;
   // This is mutable so that CalledOnValidThread can set it.
   // It's guarded by |lock_|.
   mutable base::PlatformThreadId valid_thread_id_;
 };
 
 }  // namespace net
 
 #endif  // NET_SOCKET_SSL_CLIENT_SOCKET_NSS_H_