Add an API to Pause and Resume background offlining requests.

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 <set>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 55 matching lines @@
       ++count;
     } else {
       ++iter;
     }
   }
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(callback, true, count));
 }
 
+void RequestQueueInMemoryStore::PauseRequests(
+    const std::vector<int64_t>& request_ids,
+    const UpdateCallback& callback) {
+  UpdateStatus status = SetStateForRequestIds(
+      request_ids, SavePageRequest::RequestState::PAUSED);
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, status));
+}
+
+void RequestQueueInMemoryStore::ResumeRequests(
+    const std::vector<int64_t>& request_ids,
+    const UpdateCallback& callback) {
+
+  UpdateStatus status = SetStateForRequestIds(
+      request_ids, SavePageRequest::RequestState::AVAILABLE);
+
+  base::ThreadTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::Bind(callback, status));
+}
+
+RequestQueueStore::UpdateStatus
+RequestQueueInMemoryStore::SetStateForRequestIds(
+    const std::vector<int64_t>& request_ids,
+    SavePageRequest::RequestState newState) {
+  int count = 0;
+
+  std::set<int64_t> request_id_set(request_ids.begin(), request_ids.end());
+  for (auto iter = requests_.begin(); iter != requests_.end(); ++iter) {

[Dmitry Titov, 2016/08/09 21:01:43]

I think requests_ is already a map from request_id, so it is enough to just walk
the request_ids and for each id find the request in the requests_...

[Pete Williamson, 2016/08/10 01:34:10]

Done.

+    if (request_id_set.find(iter->second.request_id()) !=
+        request_id_set.end()) {
+      // Set the state if the client ID matches.
+      iter->second.set_request_state(newState);
+      ++count;
+    }
+  }
+
+  return count > 0 ? UpdateStatus::UPDATED : UpdateStatus::FAILED;
+}
+
 void RequestQueueInMemoryStore::Reset(const ResetCallback& callback) {
   requests_.clear();
   base::ThreadTaskRunnerHandle::Get()->PostTask(FROM_HERE,
                                                 base::Bind(callback, true));
 }
 
 }  // namespace offline_pages