Flush Channel IDs when Cookies get saved to a persistent backend

net/ssl/default_channel_id_store.h

Index: net/ssl/default_channel_id_store.h
diff --git a/net/ssl/default_channel_id_store.h b/net/ssl/default_channel_id_store.h
index 7dd5dcd4c02f362fbcd54c8e1f95c9c7ee12f52c..b07495c6e8076b252bbb3aec3be01ad275b692ed 100644
--- a/net/ssl/default_channel_id_store.h
+++ b/net/ssl/default_channel_id_store.h
@@ -61,6 +61,7 @@ class NET_EXPORT DefaultChannelIDStore : public ChannelIDStore {
       const base::Closure& callback) override;
   void DeleteAll(const base::Closure& callback) override;
   void GetAllChannelIDs(const GetChannelIDListCallback& callback) override;
+  void Flush() override;
   int GetChannelIDCount() override;
   void SetForceKeepSessionState() override;
   bool IsEphemeral() override;
@@ -164,6 +165,8 @@ class NET_EXPORT DefaultChannelIDStore::PersistentStore
 
   virtual void DeleteChannelID(const ChannelID& channel_id) = 0;
 
+  virtual void Flush() = 0;
+
   // When invoked, instructs the store to keep session related data on
   // destruction.
   virtual void SetForceKeepSessionState() = 0;