[Doodle] Pull time_to_live out of DoodleConfig

components/doodle/doodle_fetcher.h

 // Copyright 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.
 
 #ifndef COMPONENTS_DOODLE_DOODLE_FETCHER_H_
 #define COMPONENTS_DOODLE_DOODLE_FETCHER_H_
 
 #include "base/callback_forward.h"
 #include "base/optional.h"
 #include "components/doodle/doodle_types.h"
 
+namespace base {
+class TimeDelta;
+}
+
 namespace doodle {
 
 // Interface for fetching the current doodle from the network.
 // It asynchronously calls a callback when fetching the doodle information from
 // the remote enpoint finishes.
 // DoodleFetcherImpl is the default implementation; this interface exists to
 // make it easy to use fakes or mocks in tests.
 class DoodleFetcher {
  public:
   // Callback that is invoked when the fetching is done.
-  // |doodle_config| will only contain a value if |state| is AVAILABLE.
+  // |time_to_live| will only be meaningful, and |doodle_config| will only
+  // contain a value, if |state| is AVAILABLE.
   using FinishedCallback = base::OnceCallback<void(
       DoodleState state,
+      base::TimeDelta time_to_live,
       const base::Optional<DoodleConfig>& doodle_config)>;

[Marc Treib, 2017/03/02 11:42:51]

As an alternative, we could wrap ttl and config into a new "DoodleResponse", but
that seems more trouble than it's worth. WDYT?

[fhorschig, 2017/03/02 13:18:08]

Doesn't sound too bad but I think for three parameters,
this solution is good.

 
   virtual ~DoodleFetcher() = default;
 
   // Fetches a doodle asynchronously. The |callback| is called with a
   // DoodleState indicating whether the request succeded in fetching a doodle.
   // If a fetch is already running, the callback will be queued and invoked with
   // the result from the next completed request.
   virtual void FetchDoodle(FinishedCallback callback) = 0;
 };
 
 }  // namespace doodle
 
 #endif  // COMPONENTS_DOODLE_DOODLE_FETCHER_H_