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..f2a9a2a4097af87e7ee17e8012597a982f07d818 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()) {

[johnme, 2015/05/14 15:22:32]

Until you implement GetDisplayedPersistentNotifications on Android, it's a
little odd that the contents of the set is always ignored. But I guess the TODO
covers this.

[Peter Beverloo, 2015/05/14 16:03:35]

Supporting the Android case is covered by
|notification_synchronization_supported| being false. Using the IDs here depends
on deterministic ID generation, which, as I said earlier, is in review now as
well.

+      prune_database_on_open_ = true;
+    }
+  }
+
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
@@ -323,6 +351,11 @@ void PlatformNotificationContextImpl::OpenDatabase(
     return;
   }
 
+  if (prune_database_on_open_) {
+    prune_database_on_open_ = false;
+    DestroyDatabase();

[johnme, 2015/05/14 15:22:32]

- Shouldn't this go after `database_.reset(new
NotificationDatabase(GetDatabasePath()));` ?

- You seem to be ignoring the case where it returns false. Though I grant that
it's not obvious how to handle that. At least add a DLOG(ERROR) perhaps?

[Peter Beverloo, 2015/05/14 16:03:35]

Done
No? We don't have to prune if the platform does not support getting the
displaying notifications, e.g. Android.

[johnme, 2015/05/14 16:40:51]

I'm talking about when DestroyDatabase returns false. You don't handle that
error currently.

+  }
+
   database_.reset(new NotificationDatabase(GetDatabasePath()));
   NotificationDatabase::Status status =
       database_->Open(true /* create_if_missing */);