Cancel prerendering when a request is paused or removed.

components/offline_pages/background/save_page_request.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/background/save_page_request.h"
 
 namespace offline_pages {
 
 SavePageRequest::SavePageRequest(int64_t request_id,
                                  const GURL& url,
@@ skipping 49 matching lines @@
   ++started_attempt_count_;
   state_ = RequestState::PRERENDERING;
 }
 
 void SavePageRequest::MarkAttemptCompleted() {
   ++completed_attempt_count_;
   state_ = RequestState::AVAILABLE;
 }
 
 void SavePageRequest::MarkAttemptAborted() {
-  DCHECK_GT(started_attempt_count_, 0);
   // We intentinally do not increment the completed_attempt_count_, since this
   // was killed before it completed, so we could use the phone or browser for
   // other things.
   state_ = RequestState::AVAILABLE;
 }
 
 void SavePageRequest::MarkAttemptPaused() {
   state_ = RequestState::PAUSED;
 }
 
 }  // namespace offline_pages