Add async variant of ProofSource::GetProof

net/quic/crypto/proof_source_chromium.cc

Index: net/quic/crypto/proof_source_chromium.cc
diff --git a/net/quic/crypto/proof_source_chromium.cc b/net/quic/crypto/proof_source_chromium.cc
index 3a62346ed34ac1c311331ae2f207bd65f1054c03..7e98c950166445bf61c108a3045031612d8e4746 100644
--- a/net/quic/crypto/proof_source_chromium.cc
+++ b/net/quic/crypto/proof_source_chromium.cc
@@ -151,4 +151,25 @@ bool ProofSourceChromium::GetProof(const IPAddress& server_ip,
   return true;
 }
 
+void ProofSourceChromium::GetProof(const IPAddress& server_ip,
+                                   const std::string& hostname,
+                                   const std::string& server_config,
+                                   QuicVersion quic_version,
+                                   base::StringPiece chlo_hash,
+                                   bool ecdsa_ok,
+                                   std::unique_ptr<Callback> callback) {
+  // As a transitional implementation, just call the synchronous version of
+  // GetProof, then invoke the callback with the results and destroy it.
+  // TODO(gredner): rework this when GetProof involves an RPC.  At that point
+  // this class will also need to store a pointer to the callback and ensure
+  // that it gets deleted after it is invoked.

[Ryan Hamilton, 2016/07/07 16:34:00]

Since proof_source_chromium is not shared, I think we'll ever end up doing an
RPC. So how 'bout just nuking this comment?

+  scoped_refptr<ProofSource::Chain> chain;
+  string signature;
+  string leaf_cert_sct;
+  const bool ok =
+      GetProof(server_ip, hostname, server_config, quic_version, chlo_hash,
+               ecdsa_ok, &chain, &signature, &leaf_cert_sct);
+  callback->Run(ok, chain, signature, leaf_cert_sct);
+}
+
 }  // namespace net