Fix QUIC crash when ProofSource::GetProof fails

net/quic/test_tools/quic_crypto_server_config_peer.h

Index: net/quic/test_tools/quic_crypto_server_config_peer.h
diff --git a/net/quic/test_tools/quic_crypto_server_config_peer.h b/net/quic/test_tools/quic_crypto_server_config_peer.h
index bd26a959e3cc728b9ffdf262807aa3bc5016d2ad..310be87bf264e5d48970d7e660b5f86b9d2cbb89 100644
--- a/net/quic/test_tools/quic_crypto_server_config_peer.h
+++ b/net/quic/test_tools/quic_crypto_server_config_peer.h
@@ -13,8 +13,7 @@ namespace test {
 // Peer for accessing otherwise private members of a QuicCryptoServerConfig.
 class QuicCryptoServerConfigPeer {
  public:
-  explicit QuicCryptoServerConfigPeer(
-      const QuicCryptoServerConfig* server_config)
+  explicit QuicCryptoServerConfigPeer(QuicCryptoServerConfig* server_config)
       : server_config_(server_config) {}
 
   // Returns the proof source.
@@ -31,6 +30,9 @@ class QuicCryptoServerConfigPeer {
   // Returns a pointer to the ProofSource object.
   ProofSource* GetProofSource() const;
 
+  // Reset the proof_source_ member.
+  void ResetProofSource(std::unique_ptr<ProofSource> proof_source);
+
   // Generates a new valid source address token.
   std::string NewSourceAddressToken(
       std::string config_id,
@@ -91,7 +93,7 @@ class QuicCryptoServerConfigPeer {
   uint32_t source_address_token_lifetime_secs();
 
  private:
-  const QuicCryptoServerConfig* server_config_;
+  QuicCryptoServerConfig* server_config_;
 };
 
 }  // namespace test