Fix QUIC crash when ProofSource::GetProof fails

net/quic/test_tools/failing_proof_source.cc

+// Copyright (c) 2017 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.
+
+#include "net/quic/test_tools/failing_proof_source.h"
+
+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;

[Jana, 2017/01/09 22:08:08]

Can you not just do this in the .h file as in the internal CL? Does compile fail
on some platform?

[danzh1, 2017/01/09 22:20:42]

Yes, chromium compiler failed in my local repo. And it doesn't allow non-empty
method body in .h file.

+}
+
+void 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,
+                                  std::unique_ptr<Callback> callback) {
+  callback->Run(false, nullptr, QuicCryptoProof(), nullptr);
+}
+
+}  // namespace test
+}  // namespace net