[Doodle] Introduce a DoodleService

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"
@@ skipping 11 matching lines @@
   // |doodle_config| will only contain a value if |state| is AVAILABLE.
   using FinishedCallback = base::OnceCallback<void(
       DoodleState state,
       const base::Optional<DoodleConfig>& doodle_config)>;
 
   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
-  // result from the next completed request.
+  // the result from the next completed request.
   virtual void FetchDoodle(FinishedCallback callback) = 0;
 };
 
 }  // namespace doodle
 
 #endif  // COMPONENTS_DOODLE_DOODLE_FETCHER_H_