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

components/offline_pages/core/background/request_coordinator.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/background/request_coordinator.h"
 
 #include <limits>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 394 matching lines @@
 }
 
 void RequestCoordinator::RemoveRequests(
     const std::vector<int64_t>& request_ids,
     const RemoveRequestsCallback& callback) {
   bool canceled = CancelActiveRequestIfItMatches(request_ids);
   queue_->RemoveRequests(
       request_ids,
       base::Bind(&RequestCoordinator::HandleRemovedRequestsAndCallback,
                  weak_ptr_factory_.GetWeakPtr(), callback,
-                 RequestNotifier::BackgroundSavePageResult::REMOVED));
+                 RequestNotifier::BackgroundSavePageResult::USER_CANCELED));
 
   // Record the network quality when this request is removed.
   if (network_quality_estimator_) {
     UMA_HISTOGRAM_ENUMERATION(
         "OfflinePages.Background.EffectiveConnectionType.RemoveRequests",
         network_quality_estimator_->GetEffectiveConnectionType(),
         net::EFFECTIVE_CONNECTION_TYPE_LAST);
   }
 
   if (canceled)
@@ skipping 693 matching lines @@
   event_logger_.RecordOfflinerResult(request.client_id().name_space, status,
                                      request.request_id());
   RecordOfflinerResultUMA(request.client_id(), request.creation_time(), status);
 }
 
 void RequestCoordinator::Shutdown() {
   network_quality_estimator_ = nullptr;
 }
 
 }  // namespace offline_pages