[Offline pages] Adding persistent request queue based on SQLite

components/offline_pages/background/request_queue_in_memory_store.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/request_queue_in_memory_store.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/offline_pages/background/save_page_request.h"
@@ skipping 25 matching lines @@
   requests_.insert(std::make_pair(request.request_id(), request));
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                 base::Bind(callback, status));
 }
 
 void RequestQueueInMemoryStore::RemoveRequests(
     const std::vector<int64_t>& request_ids,
     const RemoveCallback& callback) {
   // In case the |request_ids| is empty, the result will be true, but the count
   // of deleted pages will be empty.
   bool result = true;

[Pete Williamson, 2016/06/14 21:54:45]

If result is never false, do we still need it in the callback?
If so, should we get rid of the result variable and just pass true in the
callback for the memory queue?

[fgorski, 2016/06/14 22:38:05]

done.

   int count = 0;
   RequestsMap::iterator iter;
   for (auto request_id : request_ids) {
     iter = requests_.find(request_id);
     if (iter != requests_.end()) {
       requests_.erase(iter);
       ++count;
-    } else {
-      result = false;
     }
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(callback, result, count));
 }
 
 void RequestQueueInMemoryStore::Reset(const ResetCallback& callback) {
   requests_.clear();
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                 base::Bind(callback, true));
 }
 
 }  // namespace offline_pages