Replace ThirdPartyClientAuthenticator::TokenFetcher with a callback.

Callbacks are already used to fetch PIN. It doesn't make sense to
use a different style to fetch third-party tokens.

Review URL: https://codereview.chromium.org/1774113005

Cr-Commit-Position: refs/heads/master@{#380316}

1 files changed, 21 insertions, 0 deletions

diff --git a/remoting/protocol/authenticator.h b/remoting/protocol/authenticator.h
index febf38c..8b89111 100644
--- a/remoting/protocol/authenticator.h
+++ b/remoting/protocol/authenticator.h
@@ -25,6 +25,27 @@ typedef base::Callback<void(
     bool pairing_supported,
     const SecretFetchedCallback& secret_fetched_callback)> FetchSecretCallback;
 
+// Callback passed to |FetchTokenCallback|, and called once the client
+// authentication finishes. |token| is an opaque string that should be sent
+// directly to the host. |shared_secret| should be used by the client to
+// create a V2Authenticator. In case of failure, the callback is called with
+// an empty |token| and |shared_secret|.
+typedef base::Callback<void(const std::string& token,
+                            const std::string& shared_secret)>
+    ThirdPartyTokenFetchedCallback;
+
+// Fetches a third party token from |token_url|. |host_public_key| is sent to
+// the server so it can later authenticate the host. |scope| is a string with a
+// space-separated list of attributes for this connection (e.g.
+// "hostjid:abc@example.com/123 clientjid:def@example.org/456".
+// |token_fetched_callback| is called when the client authentication ends, on
+// the same thread on which FetchThirdPartyTokenCallback was originally called.
+typedef base::Callback<void(
+    const std::string& token_url,
+    const std::string& scope,
+    const ThirdPartyTokenFetchedCallback& token_fetched_callback)>
+    FetchThirdPartyTokenCallback;
+
 // Authenticator is an abstract interface for authentication protocol
 // implementations. Different implementations of this interface may be used on
 // each side of the connection depending of type of the auth protocol. Client