PrerenderingLoader initial integration with PrerenderManager/PrerenderHandle

components/offline_pages/background/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 COMPONENTS_OFFLINE_PAGES_BACKGROUND_OFFLINER_H_
 #define COMPONENTS_OFFLINE_PAGES_BACKGROUND_OFFLINER_H_
 
 #include "base/callback.h"
 
 namespace offline_pages {
 
 class SavePageRequest;
 
 // Interface of a class responsible for constructing an offline page given
 // a request with a URL.
 class Offliner {
  public:
-  // Completion status of processing an offline page request.
-  enum CompletionStatus {
-    SAVED = 0,
-    CANCELED = 1,
-    FAILED_CONSIDER_RETRY = 2,
-    FAILED_DO_NOT_RETRY = 3,
+  // Status of processing an offline page request.
+  enum class RequestStatus {
+    UNKNOWN,                // No status determined/reported yet.
+    LOADED,                 // Page loaded but not (yet) saved.
+    SAVED,                  // Offline page snapshot saved.
+    CANCELED,               // Request was canceled.
+    FAILED_CONSIDER_RETRY,  // Failed in a way that is subject to retry.

[gabadie, 2016/05/13 07:55:38]

Sorry, but where is this guy used?

[dougarnett, 2016/05/13 17:03:59]

The RequestCoordinator (not part of this CL) uses this to decide whether to drop
the offlining request from the RequestQueue or to keep it for a future attempt
(subject to retry count).

The idea is for the PrerenderingLoader to bucket the prerender::FinalStatus
codes into whether the operation might be subject to retry or not (TODO in this
CL).

If/when we add a server-rendering Offliner implementation, it would map its
result codes into these buckets also to give the RequestCoordinator the same
type of recommendation.

+    FAILED_DO_NOT_RETRY,    // Failed in a way that is not subject to retry.
   };
 
   // Reports the completion status of a request.
   // TODO(dougarnett): consider passing back a request id instead of request.
-  typedef base::Callback<void(const SavePageRequest&, CompletionStatus)>
+  typedef base::Callback<void(const SavePageRequest&, RequestStatus)>
       CompletionCallback;
 
   Offliner() {}
   virtual ~Offliner() {}
 
   // Processes |request| to load and save an offline page.
   // Returns whether the request was accepted or not.
   virtual bool LoadAndSave(
       const SavePageRequest& request,
       const CompletionCallback& callback) = 0;
 
   // Clears the currently processing request, if any.
   virtual void Cancel() = 0;
 
   // TODO(dougarnett): add policy support methods.
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_BACKGROUND_OFFLINER_H_