Change the prototype of ChannelIDSource::GetChannelIDKey() to allow an

net/quic/crypto/channel_id.h

 // Copyright 2013 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.
 
 #ifndef NET_QUIC_CRYPTO_CHANNEL_ID_H_
 #define NET_QUIC_CRYPTO_CHANNEL_ID_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_piece.h"
 #include "net/base/net_export.h"
+#include "net/quic/quic_types.h"
 
 namespace net {
 
 // ChannelIDKey is an interface that supports signing with and serializing a
 // ChannelID key.
 class NET_EXPORT_PRIVATE ChannelIDKey {
  public:
   virtual ~ChannelIDKey() { }
 
   // Sign signs |signed_data| using the ChannelID private key and puts the
   // signature into |out_signature|. It returns true on success.
   virtual bool Sign(base::StringPiece signed_data,
-                    std::string* out_signature) = 0;
+                    std::string* out_signature) const = 0;
 
   // SerializeKey returns the serialized ChannelID public key.
-  virtual std::string SerializeKey() = 0;
+  virtual std::string SerializeKey() const = 0;
+};
+
+// ChannelIDSourceCallback provides a generic mechanism for a ChannelIDSource
+// to call back after an asynchronous GetChannelIDKey operation.
+class ChannelIDSourceCallback {
+ public:
+  virtual ~ChannelIDSourceCallback() {}
+
+  // Run is called on the original thread to mark the completion of an
+  // asynchonous GetChannelIDKey operation. If |*channel_id_key| is not NULL
+  // then the channel ID lookup is successful. |Run| may take ownership of
+  // |*channel_id_key| by calling |release| on it.
+  virtual void Run(scoped_ptr<ChannelIDKey>* channel_id_key) = 0;
 };
 
 // ChannelIDSource is an abstract interface by which a QUIC client can obtain
 // a ChannelIDKey for a given hostname.
 class NET_EXPORT_PRIVATE ChannelIDSource {
  public:
   virtual ~ChannelIDSource() {}
 
   // GetChannelIDKey looks up the ChannelIDKey for |hostname|. On success it
-  // returns true and stores the ChannelIDKey in |*channel_id|.
-  virtual bool GetChannelIDKey(const std::string& hostname,
-                               scoped_ptr<ChannelIDKey>* channel_id_key) = 0;
+  // returns QUIC_SUCCESS and stores the ChannelIDKey in |*channel_id_key|,
+  // which the caller takes ownership of. On failure, it returns QUIC_FAILURE.
+  //
+  // This function may also return QUIC_PENDING, in which case the
+  // ChannelIDSource will call back, on the original thread, via |callback|
+  // when complete. In this case, the ChannelIDSource will take ownership of
+  // |callback|.
+  virtual QuicAsyncStatus GetChannelIDKey(
+      const std::string& hostname,
+      scoped_ptr<ChannelIDKey>* channel_id_key,
+      ChannelIDSourceCallback* callback) = 0;
 };
 
 // ChannelIDVerifier verifies ChannelID signatures.
 class NET_EXPORT_PRIVATE ChannelIDVerifier {
  public:
   // kContextStr is prepended to the data to be signed in order to ensure that
   // a ChannelID signature cannot be used in a different context. (The
   // terminating NUL byte is inclued.)
   static const char kContextStr[];
   // kClientToServerStr follows kContextStr to specify that the ChannelID is
@@ skipping 16 matching lines @@
                         base::StringPiece signature,
                         bool is_channel_id_signature);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ChannelIDVerifier);
 };
 
 }  // namespace net
 
 #endif  // NET_QUIC_CRYPTO_CHANNEL_ID_H_