Revert of PrerenderingLoader initial integration with PrerenderManager/PrerenderHandle

components/offline_pages/background/offliner.h

Index: components/offline_pages/background/offliner.h
diff --git a/components/offline_pages/background/offliner.h b/components/offline_pages/background/offliner.h
index ead1adfa503113459cc5ff016081727ce98f6376..e24506075929e32a397a30ef24ecc81c1450f289 100644
--- a/components/offline_pages/background/offliner.h
+++ b/components/offline_pages/background/offliner.h
@@ -15,19 +15,18 @@
 // a request with a URL.
 class Offliner {
  public:
-  // 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,    // Request failed.
-    // TODO(dougarnett): Define a retry-able failure status.
+  // Completion status of processing an offline page request.
+  enum CompletionStatus {
+    SAVED = 0,
+    CANCELED = 1,
+    FAILED_CONSIDER_RETRY = 2,
+    FAILED_DO_NOT_RETRY = 3,
+    UNKNOWN = 4,
   };
 
   // Reports the completion status of a request.
   // TODO(dougarnett): consider passing back a request id instead of request.
-  typedef base::Callback<void(const SavePageRequest&, RequestStatus)>
+  typedef base::Callback<void(const SavePageRequest&, CompletionStatus)>
       CompletionCallback;
 
   Offliner() {}