Deprecate FLAGS_quic_reloadable_flag_enable_async_get_proof

net/quic/test_tools/failing_proof_source.cc

Index: net/quic/test_tools/failing_proof_source.cc
diff --git a/net/quic/test_tools/failing_proof_source.cc b/net/quic/test_tools/failing_proof_source.cc
index 53b69e19c856a40f8479cba4ae12b1104edd5ffc..a45bf5264dea1ffca7bf074c067ad76b1092ae23 100644
--- a/net/quic/test_tools/failing_proof_source.cc
+++ b/net/quic/test_tools/failing_proof_source.cc
@@ -7,18 +7,6 @@
 namespace net {
 namespace test {
 
-bool FailingProofSource::GetProof(
-    const QuicSocketAddress& server_address,
-    const std::string& hostname,
-    const std::string& server_config,
-    QuicVersion quic_version,
-    base::StringPiece chlo_hash,
-    const QuicTagVector& connection_options,
-    QuicReferenceCountedPointer<ProofSource::Chain>* out_chain,
-    QuicCryptoProof* out_proof) {
-  return false;
-}
-
 void FailingProofSource::GetProof(const QuicSocketAddress& server_address,
                                   const std::string& hostname,
                                   const std::string& server_config,