Adds PrerenderingOffliner implementation for handling Loader callbacks and then performing SavePage…

chrome/browser/android/offline_pages/prerendering_offliner.h

 // 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 CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_OFFLINER_H_
 #define CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_OFFLINER_H_
 
 #include <memory>
 
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/android/offline_pages/prerendering_loader.h"
 #include "components/offline_pages/background/offliner.h"
 #include "components/offline_pages/offline_page_model.h"
+#include "components/offline_pages/offline_page_types.h"
 
 namespace content {
 class BrowserContext;
 class WebContents;
 }  // namespace content
 
 namespace offline_pages {
 
 class OfflinerPolicy;
 
 // An Offliner implementation that attempts client-side rendering and saving
 // of an offline page. It uses the PrerenderingLoader to load the page and
-// the OfflinePageModel to save it.
+// the OfflinePageModel to save it. Only one request may be active at a time.
 class PrerenderingOffliner : public Offliner {
  public:
   PrerenderingOffliner(content::BrowserContext* browser_context,
                        const OfflinerPolicy* policy,
                        OfflinePageModel* offline_page_model);
   ~PrerenderingOffliner() override;
 
   // Offliner implementation.
   bool LoadAndSave(const SavePageRequest& request,
                    const CompletionCallback& callback) override;
   void Cancel() override;
 
   // Allows a loader to be injected for testing. This may only be done once
   // and must be called before any of the Offliner interface methods are called.
   void SetLoaderForTesting(std::unique_ptr<PrerenderingLoader> loader);
 
+ protected:
+  // Internal method for OfflinePageModel's check if url can be saved.
+  // Exposed for unit testing.
+  // TODO(dougarnett): Consider making OfflinePageModel mockable instead.
+  virtual bool CanSavePage(const GURL& url);
+
+  // Internal method for requesting OfflinePageModel to save page.
+  // Exposed for unit testing.
+  // TODO(dougarnett): Consider making OfflinePageModel mockable instead.
+  virtual void SavePage(const GURL& url,
+                        const ClientId& client_id,
+                        std::unique_ptr<OfflinePageArchiver> archiver,
+                        const SavePageCallback& callback);
+
  private:
-  void OnLoadPageDone(const Offliner::RequestStatus load_status,
-                      content::WebContents* contents);
+  // Callback logic for PrerenderingLoader::LoadPage().
+  void OnLoadPageDone(const SavePageRequest& request,
+                      const CompletionCallback& completion_callback,
+                      Offliner::RequestStatus load_status,
+                      content::WebContents* web_contents);
+
+  // Callback logic for OfflinePageModel::SavePage().
+  void OnSavePageDone(const SavePageRequest& request,
+                      const CompletionCallback& completion_callback,
+                      SavePageResult save_result,
+                      int64_t offline_id);
 
   PrerenderingLoader* GetOrCreateLoader();
+  void SetPendingRequest(int64_t request_id);
+  void ClearPendingRequest();
 
   // Not owned.
   content::BrowserContext* browser_context_;
   // Not owned.
   OfflinePageModel* offline_page_model_;
   // Lazily created.
   std::unique_ptr<PrerenderingLoader> loader_;
+  // Tracks pending request, if any. Not owned.
+  // May be used to ensure a callback applies to the pending request (e.g., in
+  // case we receive a save page callback for an old, canceled request).
+  SavePageRequest const* pending_request_;
   base::WeakPtrFactory<PrerenderingOffliner> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PrerenderingOffliner);
 };
 
 }  // namespace offline_pages
 
 #endif  // CHROME_BROWSER_ANDROID_OFFLINE_PAGES_PRERENDERING_OFFLINER_H_