Eagerly delete replaced notifications from the database

content/browser/notifications/platform_notification_context_impl.cc

 // Copyright 2015 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 "content/browser/notifications/platform_notification_context_impl.h"
 
 #include "base/bind_helpers.h"
 #include "base/files/file_util.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
@@ skipping 221 matching lines @@
                  this, origin, database_data, callback),
       base::Bind(callback, false /* success */, 0 /* notification_id */));
 }
 
 void PlatformNotificationContextImpl::DoWriteNotificationData(
     const GURL& origin,
     const NotificationDatabaseData& database_data,
     const WriteResultCallback& callback) {
   DCHECK(task_runner_->RunsTasksOnCurrentThread());
 
+  // Eagerly delete data for replaced notifications from the database.
+  if (!database_data.notification_data.tag.empty()) {
+    std::set<int64_t> deleted_notification_set;
+    NotificationDatabase::Status delete_status =
+        database_->DeleteAllNotificationDataForOrigin(
+            origin, database_data.notification_data.tag,
+            &deleted_notification_set);
+
+    UMA_HISTOGRAM_ENUMERATION("Notifications.Database.DeleteBeforeWriteResult",
+                              delete_status,
+                              NotificationDatabase::STATUS_COUNT);
+
+    // Unless the database was corrupted following this change, there is no
+    // reason to bail out here in event of failure because the notification
+    // display logic will handle notification replacement for the user.
+    if (delete_status == NotificationDatabase::STATUS_ERROR_CORRUPTED) {
+      DestroyDatabase();
+
+      BrowserThread::PostTask(
+          BrowserThread::IO, FROM_HERE,
+          base::Bind(callback, false /* success */, 0 /* notification_id */));
+      return;
+    }
+  }
+
   int64_t notification_id = 0;
   NotificationDatabase::Status status =
       database_->WriteNotificationData(origin, database_data, &notification_id);
 
   UMA_HISTOGRAM_ENUMERATION("Notifications.Database.WriteResult", status,
                             NotificationDatabase::STATUS_COUNT);
 
   if (status == NotificationDatabase::STATUS_OK) {
     DCHECK_GT(notification_id, 0);
     BrowserThread::PostTask(
@@ skipping 187 matching lines @@
 
   return path_.Append(kPlatformNotificationsDirectory);
 }
 
 void PlatformNotificationContextImpl::SetTaskRunnerForTesting(
     const scoped_refptr<base::SequencedTaskRunner>& task_runner) {
   task_runner_ = task_runner;
 }
 
 }  // namespace content