Beginnings of synchronizing notifications in the notification database.

content/browser/notifications/platform_notification_context_impl.cc

Index: content/browser/notifications/platform_notification_context_impl.cc
diff --git a/content/browser/notifications/platform_notification_context_impl.cc b/content/browser/notifications/platform_notification_context_impl.cc
index db6f1361a16d6ca41bf25abf7a2883ee0e552741..bdeabce55af4feff0bc4bf6d0c952c29e1507c48 100644
--- a/content/browser/notifications/platform_notification_context_impl.cc
+++ b/content/browser/notifications/platform_notification_context_impl.cc
@@ -11,7 +11,9 @@
 #include "content/browser/notifications/notification_database.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/content_browser_client.h"
 #include "content/public/browser/notification_database_data.h"
+#include "content/public/browser/platform_notification_service.h"
 
 using base::DoNothing;
 
@@ -24,8 +26,10 @@ const base::FilePath::CharType kPlatformNotificationsDirectory[] =
 
 PlatformNotificationContextImpl::PlatformNotificationContextImpl(
     const base::FilePath& path,
+    BrowserContext* browser_context,
     const scoped_refptr<ServiceWorkerContextWrapper>& service_worker_context)
     : path_(path),
+      browser_context_(browser_context),
       service_worker_context_(service_worker_context) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 }
@@ -43,6 +47,30 @@ PlatformNotificationContextImpl::~PlatformNotificationContextImpl() {
 
 void PlatformNotificationContextImpl::Initialize() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  PlatformNotificationService* service =
+      GetContentClient()->browser()->GetPlatformNotificationService();
+  if (service) {
+    std::set<std::string> displayed_notifications;
+
+    bool notification_synchronization_supported =
+        service->GetDisplayedPersistentNotifications(browser_context_,
+                                                     &displayed_notifications);
+
+    // Synchronize the notifications stored in the database with the set of
+    // displaying notifications in |displayed_notifications|. This is necessary
+    // because flakiness may cause a platform to inform Chrome of a notification
+    // that has since been closed, or because the platform does not support
+    // notifications that exceed the lifetime of the browser process.
+
+    // TODO(peter): Synchronizing the actual notifications will be done when the
+    // persistent notification ids are stable. For M44 we need to support the
+    // case where there may be no notifications after a Chrome restart.
+    if (notification_synchronization_supported &&
+        !displayed_notifications.size()) {
+      prune_database_on_open_ = true;
+    }
+  }
+
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
@@ -330,10 +358,23 @@ void PlatformNotificationContextImpl::OpenDatabase(
   UMA_HISTOGRAM_ENUMERATION("Notifications.Database.OpenResult",
                             status, NotificationDatabase::STATUS_COUNT);
 
+  // TODO(peter): Do finer-grained synchronization here.
+  if (prune_database_on_open_) {
+    prune_database_on_open_ = false;
+    DestroyDatabase();
+
+    database_.reset(new NotificationDatabase(GetDatabasePath()));
+    status = database_->Open(true /* create_if_missing */);
+
+    // TODO(peter): Find the appropriate UMA to cover in regards to
+    // synchronizing notifications after the implementation is complete.
+  }
+
   // When the database could not be opened due to corruption, destroy it, blow
   // away the contents of the directory and try re-opening the database.
   if (status == NotificationDatabase::STATUS_ERROR_CORRUPTED) {
     if (DestroyDatabase()) {
+      database_.reset(new NotificationDatabase(GetDatabasePath()));
       status = database_->Open(true /* create_if_missing */);
 
       UMA_HISTOGRAM_ENUMERATION(