[Offline pages] Eliminating duplicate notifications, by fixing request queue store

components/offline_pages/background/request_queue_store_sql.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_store_sql.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/location.h"
@@ skipping 96 matching lines @@
 }
 
 void BuildFailedResultList(const std::vector<int64_t>& request_ids,
                            RequestQueue::UpdateMultipleRequestResults results) {
   results.clear();
   for (int64_t request_id : request_ids)
     results.push_back(std::make_pair(
         request_id, RequestQueue::UpdateRequestResult::STORE_FAILURE));
 }
 
-bool DeleteRequestById(sql::Connection* db, int64_t request_id) {
+RequestQueue::UpdateRequestResult DeleteRequestById(sql::Connection* db,
+                                                    int64_t request_id) {
   const char kSql[] =
       "DELETE FROM " REQUEST_QUEUE_TABLE_NAME " WHERE request_id=?";
   sql::Statement statement(db->GetCachedStatement(SQL_FROM_HERE, kSql));
   statement.BindInt64(0, request_id);
-  return statement.Run();
+  if (!statement.Run())
+    return RequestQueue::UpdateRequestResult::STORE_FAILURE;
+  else if (db->GetLastChangeCount() == 0)
+    return RequestQueue::UpdateRequestResult::REQUEST_DOES_NOT_EXIST;
+  else
+    return RequestQueue::UpdateRequestResult::SUCCESS;
 }
 
 bool ChangeRequestState(sql::Connection* db,
                         const int64_t request_id,
                         const SavePageRequest::RequestState new_state) {
   const char kSql[] = "UPDATE " REQUEST_QUEUE_TABLE_NAME
                       " SET state=?"
                       " WHERE request_id=?";
   sql::Statement statement(db->GetCachedStatement(SQL_FROM_HERE, kSql));
   statement.BindInt64(0, static_cast<int64_t>(new_state));
@@ skipping 10 matching lines @@
   sql::Transaction transaction(db);
   if (!transaction.Begin()) {
     BuildFailedResultList(request_ids, results);
     return false;
   }
 
   // Read the request before we delete it, and if the delete worked, put it on
   // the queue of requests that got deleted.
   for (int64_t request_id : request_ids) {
     SavePageRequest request = GetOneRequest(db, request_id);
-    RequestQueue::UpdateRequestResult result;
-    if (DeleteRequestById(db, request_id)) {
-      result = RequestQueue::UpdateRequestResult::SUCCESS;
+    RequestQueue::UpdateRequestResult result =
+        DeleteRequestById(db, request_id);
+    results.push_back(std::make_pair(request_id, result));
+    if (result == RequestQueue::UpdateRequestResult::SUCCESS)
       requests.push_back(request);
-    } else {
-      result = RequestQueue::UpdateRequestResult::REQUEST_DOES_NOT_EXIST;
-    }
-    results.push_back(std::make_pair(request_id, result));
-    requests.push_back(request);
   }
 
   if (!transaction.Commit()) {
     requests.clear();
     BuildFailedResultList(request_ids, results);
     return false;
   }
 
   return true;
 }
@@ skipping 283 matching lines @@
 }
 
 void RequestQueueStoreSQL::OnResetDone(const ResetCallback& callback,
                                        bool success) {
   // Complete connection initialization post reset.
   OnOpenConnectionDone(success);
   callback.Run(success);
 }
 
 }  // namespace offline_pages