Remove pure virtual methods from TlsHandshaker

These methods serve no purpose except to confuse readers of the relationship
between QuicCryptoStream (and its subclasses), the subclasses of
TlsHandshaker, and the relationships between those two sets of subclasses.

PiperOrigin-RevId: 332112054
Change-Id: I01e281612a8787d3f5731d2ce8b7c0ac03f87c7e
diff --git a/quic/core/tls_handshaker.h b/quic/core/tls_handshaker.h
index 3d5f1e2..282c89d 100644
--- a/quic/core/tls_handshaker.h
+++ b/quic/core/tls_handshaker.h
@@ -44,13 +44,9 @@
     return parser_error_detail_;
   }
 
-  // From QuicCryptoStream
-  virtual bool encryption_established() const = 0;
-  virtual bool one_rtt_keys_available() const = 0;
-  virtual const QuicCryptoNegotiatedParameters& crypto_negotiated_params()
-      const = 0;
-  virtual CryptoMessageParser* crypto_message_parser() { return this; }
-  virtual HandshakeState GetHandshakeState() const = 0;
+  // The following methods provide implementations to subclasses of
+  // TlsHandshaker which use them to implement methods of QuicCryptoStream.
+  CryptoMessageParser* crypto_message_parser() { return this; }
   size_t BufferSizeLimitForLevel(EncryptionLevel level) const;
 
  protected: