Implement first version of OfflinePageSuggestionsProvider

components/ntp_snippets/offline_pages/offline_page_suggestions_provider.h

Index: components/ntp_snippets/offline_pages/offline_page_suggestions_provider.h
diff --git a/components/ntp_snippets/offline_pages/offline_page_suggestions_provider.h b/components/ntp_snippets/offline_pages/offline_page_suggestions_provider.h
new file mode 100644
index 0000000000000000000000000000000000000000..a82f4883e9fcc996fcd8f51694a2648525a907b2
--- /dev/null
+++ b/components/ntp_snippets/offline_pages/offline_page_suggestions_provider.h
@@ -0,0 +1,80 @@
+// Copyright 2016 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_NTP_SNIPPETS_OFFLINE_PAGES_OFFLINE_PAGE_SUGGESTIONS_PROVIDER_H_
+#define COMPONENTS_NTP_SNIPPETS_OFFLINE_PAGES_OFFLINE_PAGE_SUGGESTIONS_PROVIDER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "components/keyed_service/core/keyed_service.h"
+#include "components/ntp_snippets/content_suggestion.h"
+#include "components/ntp_snippets/content_suggestions_category.h"
+#include "components/ntp_snippets/content_suggestions_category_status.h"
+#include "components/ntp_snippets/content_suggestions_provider.h"
+#include "components/offline_pages/offline_page_item.h"

[Marc Treib, 2016/07/14 12:16:53]

nit: Not required I think

[Philipp Keck, 2016/07/14 13:46:02]

Done.

+#include "components/offline_pages/offline_page_model.h"
+#include "components/offline_pages/offline_page_types.h"
+
+namespace gfx {
+class Image;
+}
+
+namespace ntp_snippets {
+
+// Provides content suggestions from the offline pages model.
+// Currently, those are only the pages that the user last navigated to in an
+// open tab and offlined bookmarks.
+class OfflinePageSuggestionsProvider
+    : public KeyedService,
+      public ContentSuggestionsProvider,
+      public offline_pages::OfflinePageModel::Observer {
+ public:
+  using ImageFetchedCallback =
+      base::Callback<void(const std::string& suggestion_id, const gfx::Image&)>;

[Marc Treib, 2016/07/14 12:16:53]

Is this required? It's already defined in ContentSuggestionsProvider.
(If a "using" is required at all, then at least make it "using
ImageFetchedCallback = ContentSuggestionsProvider::ImageFetchedCallback")

[Philipp Keck, 2016/07/14 13:46:03]

Done. Also removed from NTPSnippetsService.

+
+  OfflinePageSuggestionsProvider(
+      offline_pages::OfflinePageModel* offline_page_model);
+  ~OfflinePageSuggestionsProvider() override;
+
+  // Inherited from KeyedService.
+  void Shutdown() override;
+
+ private:
+  // ContentSuggestionsProvider implementation
+  void SetObserver(ContentSuggestionsProvider::Observer* observer) override;
+  ContentSuggestionsCategoryStatus GetCategoryStatus(
+      ContentSuggestionsCategory category) override;
+  void DiscardSuggestion(const std::string& suggestion_id) override;
+  void FetchSuggestionImage(const std::string& suggestion_id,
+                            const ImageFetchedCallback& callback) override;
+  void ClearCachedSuggestionsForDebugging() override;
+  void ClearDiscardedSuggestionsForDebugging() override;
+
+  // OfflinePageModel::Observer implementation
+  void OfflinePageModelLoaded(offline_pages::OfflinePageModel* model) override;
+  void OfflinePageModelChanged(offline_pages::OfflinePageModel* model) override;
+  void OfflinePageDeleted(int64_t offline_id,
+                          const offline_pages::ClientId& client_id) override;
+
+  // Queries the OfflinePageModel for offline pages

[Marc Treib, 2016/07/14 12:16:53]

nit: period after comment

[Philipp Keck, 2016/07/14 13:46:03]

Done.

+  void FetchOfflinePages();
+
+  // Callback from the OfflinePageModel
+  void OnOfflinePagesLoaded(
+      const offline_pages::MultipleOfflinePageItemResult& result);
+
+  ContentSuggestionsCategoryStatus category_status_;
+
+  ContentSuggestionsProvider::Observer* observer_ = nullptr;

[Marc Treib, 2016/07/14 12:16:53]

Please let's keep all initialization in one place.

[Philipp Keck, 2016/07/14 13:46:02]

Done.

+
+  offline_pages::OfflinePageModel* offline_page_model_;
+
+  DISALLOW_COPY_AND_ASSIGN(OfflinePageSuggestionsProvider);
+};
+
+}  // namespace ntp_snippets
+
+#endif  // COMPONENTS_NTP_SNIPPETS_OFFLINE_PAGES_OFFLINE_PAGE_SUGGESTIONS_PROVIDER_H_