[Offline pages] Rename REMOVED to USER_CANCELED and add better foot note descriptions for histogram…

components/offline_pages/core/downloads/download_notifying_observer.cc

 // 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.
 
 #include "components/offline_pages/core/downloads/download_notifying_observer.h"
 
 #include "base/memory/ptr_util.h"
 #include "components/offline_pages/core/background/request_coordinator.h"
 #include "components/offline_pages/core/background/save_page_request.h"
 #include "components/offline_pages/core/client_policy_controller.h"
@@ skipping 62 matching lines @@
 }
 
 void DownloadNotifyingObserver::OnCompleted(
     const SavePageRequest& request,
     RequestCoordinator::BackgroundSavePageResult status) {
   DCHECK(notifier_.get());
   if (!IsVisibleInUI(request.client_id()))
     return;
   if (status == RequestCoordinator::BackgroundSavePageResult::SUCCESS)
     notifier_->NotifyDownloadSuccessful(DownloadUIItem(request));
-  else if (status == RequestCoordinator::BackgroundSavePageResult::REMOVED)
+  else if (status ==
+           RequestCoordinator::BackgroundSavePageResult::USER_CANCELED)
     notifier_->NotifyDownloadCanceled(DownloadUIItem(request));
   else
     notifier_->NotifyDownloadFailed(DownloadUIItem(request));
 }
 
 bool DownloadNotifyingObserver::IsVisibleInUI(const ClientId& page) {
   return policy_controller_->IsSupportedByDownload(page.name_space) &&
          base::IsValidGUID(page.id);
 }
 
 // Calls the appropriate notifier method depending upon the state of the
 // request. For example, an AVAILABLE request is not active (aka, pending)
 // which the notifier understands as an Interrupted operation vs. one that
 // has Progress or is Paused.
 void DownloadNotifyingObserver::NotifyRequestStateChange(
     const SavePageRequest& request) {
   if (request.request_state() == SavePageRequest::RequestState::PAUSED)
     notifier_->NotifyDownloadPaused(DownloadUIItem(request));
   else if (request.request_state() == SavePageRequest::RequestState::AVAILABLE)
     notifier_->NotifyDownloadInterrupted(DownloadUIItem(request));
   else
     notifier_->NotifyDownloadProgress(DownloadUIItem(request));
 }
 
 }  // namespace offline_pages