Notify GCMAppHandlers when the store is reset, so they clear cached IDs

components/invalidation/impl/gcm_network_channel.cc

Index: components/invalidation/impl/gcm_network_channel.cc
diff --git a/components/invalidation/impl/gcm_network_channel.cc b/components/invalidation/impl/gcm_network_channel.cc
index 6204ecc957e97051e99588e5ad016ed8b843616e..5b2aafeb81a01c78ad6d420f9ff989f56673e8ed 100644
--- a/components/invalidation/impl/gcm_network_channel.cc
+++ b/components/invalidation/impl/gcm_network_channel.cc
@@ -121,8 +121,10 @@ GCMNetworkChannel::GCMNetworkChannel(
       diagnostic_info_(this),
       weak_factory_(this) {
   net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
-  delegate_->Initialize(base::Bind(&GCMNetworkChannel::OnConnectionStateChanged,
-                                   weak_factory_.GetWeakPtr()));
+  delegate_->Initialize(
+      base::Bind(&GCMNetworkChannel::OnConnectionStateChanged,
+                 weak_factory_.GetWeakPtr()),
+      base::Bind(&GCMNetworkChannel::OnStoreReset, weak_factory_.GetWeakPtr()));
   Register();
 }
 
@@ -194,7 +196,7 @@ void GCMNetworkChannel::OnGetTokenComplete(
     const GoogleServiceAuthError& error,
     const std::string& token) {
   DCHECK(CalledOnValidThread());
-  if (cached_message_.empty()) {
+  if (cached_message_.empty() || registration_id_.empty()) {
     // Nothing to do.
     return;
   }
@@ -302,6 +304,11 @@ void GCMNetworkChannel::OnConnectionStateChanged(bool online) {
   UpdateGcmChannelState(online);
 }
 
+void GCMNetworkChannel::OnStoreReset() {
+  // TODO(crbug.com/661660): Tell server the registration ID is no longer valid.
+  registration_id_.clear();
+}
+
 void GCMNetworkChannel::OnNetworkChanged(
     net::NetworkChangeNotifier::ConnectionType connection_type) {
   // Network connection is restored. Let's notify cacheinvalidations so it has