[Suggestions] Adding a Thumbnail Manager for the Suggestions Service

chrome/browser/search/suggestions/suggestions_service.h

 // Copyright 2014 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 CHROME_BROWSER_SEARCH_SUGGESTIONS_SUGGESTIONS_SERVICE_H_
 #define CHROME_BROWSER_SEARCH_SUGGESTIONS_SUGGESTIONS_SERVICE_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "chrome/browser/search/suggestions/proto/suggestions.pb.h"
+#include "chrome/browser/search/suggestions/thumbnail_manager.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "net/url_request/url_fetcher_delegate.h"
+#include "ui/gfx/image/image_skia.h"
 #include "url/gurl.h"
 
 class Profile;
 
 namespace suggestions {
 
 extern const char kSuggestionsFieldTrialName[];
 extern const char kSuggestionsFieldTrialURLParam[];
 extern const char kSuggestionsFieldTrialStateParam[];
 extern const char kSuggestionsFieldTrialStateEnabled[];
 
 // An interface to fetch server suggestions asynchronously.
 class SuggestionsService : public KeyedService, public net::URLFetcherDelegate {
  public:
   typedef base::Callback<void(const SuggestionsProfile&)> ResponseCallback;
 
   explicit SuggestionsService(Profile* profile);
   virtual ~SuggestionsService();
 
   // Whether this service is enabled.
   static bool IsEnabled();
 
   // Request suggestions data, which will be passed to |callback|. Initiates a
   // fetch request unless a pending one exists. To prevent multiple requests,
   // we place all |callback|s in a queue and update them simultaneously when
   // fetch request completes.
   void FetchSuggestionsData(ResponseCallback callback);
 
+  // Retrieves stored thumbnail for website |url| asynchronously. Calls
+  // |callback| with Bitmap pointer if found, and NULL otherwise.
+  void GetPageThumbnail(
+      const GURL& url,
+      base::Callback<void(const GURL&, const SkBitmap*)> callback);
+
  private:
   FRIEND_TEST_ALL_PREFIXES(SuggestionsServiceTest, FetchSuggestionsData);
 
   // net::URLFetcherDelegate implementation.
   // Called when fetch request completes. Parses the received suggestions data,
   // and dispatches them to callbacks stored in queue.
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
   // KeyedService implementation.
   virtual void Shutdown() OVERRIDE;
 
   // Contains the current suggestions fetch request. Will only have a value
   // while a request is pending, and will be reset by |OnURLFetchComplete|.
   scoped_ptr<net::URLFetcher> pending_request_;
 
   // The start time of the previous suggestions request. This is used to measure
   // the latency of requests. Initially zero.
   base::TimeTicks last_request_started_time_;
 
   // The URL to fetch suggestions data from.
   GURL suggestions_url_;
 
   // Queue of callbacks. These are flushed when fetch request completes.
   std::vector<ResponseCallback> waiting_requestors_;
 
+  // Used to obtain server thumbnails, if available.
+  scoped_ptr<ThumbnailManager> thumbnail_manager_;
+
   Profile* profile_;
 
   DISALLOW_COPY_AND_ASSIGN(SuggestionsService);
 };
 
 }  // namespace suggestions
 
 #endif  // CHROME_BROWSER_SEARCH_SUGGESTIONS_SUGGESTIONS_SERVICE_H_