Push API: Validate storage before returning cached subscriptions

components/gcm_driver/gcm_client_impl.cc

Index: components/gcm_driver/gcm_client_impl.cc
diff --git a/components/gcm_driver/gcm_client_impl.cc b/components/gcm_driver/gcm_client_impl.cc
index 5420646009c631e2568e754586fe0e6360884ad9..a609cc902adc33728364bd77e8bd9e93afba6661 100644
--- a/components/gcm_driver/gcm_client_impl.cc
+++ b/components/gcm_driver/gcm_client_impl.cc
@@ -999,6 +999,41 @@ void GCMClientImpl::OnRegisterCompleted(
     pending_registration_requests_.erase(iter);
 }
 
+bool GCMClientImpl::ValidateRegistration(
+    const linked_ptr<RegistrationInfo>& registration_info,
+    const std::string& registration_id) {
+  DCHECK_EQ(state_, READY);
+
+  // Must have a cached registration.
+  RegistrationInfoMap::const_iterator registrations_iter =
+      registrations_.find(registration_info);
+  if (registrations_iter == registrations_.end())
+    return false;
+
+  // Cached registration ID must match.
+  const std::string& cached_registration_id = registrations_iter->second;
+  if (registration_id != cached_registration_id)
+    return false;
+
+  // For GCM registration, we also match the sender IDs since multiple
+  // registrations are not supported.
+  const GCMRegistrationInfo* gcm_registration_info =
+      GCMRegistrationInfo::FromRegistrationInfo(registration_info.get());
+  if (gcm_registration_info) {
+    const GCMRegistrationInfo* cached_gcm_registration_info =
+        GCMRegistrationInfo::FromRegistrationInfo(
+            registrations_iter->first.get());
+    DCHECK(cached_gcm_registration_info);
+    if (cached_gcm_registration_info &&

[Peter Beverloo, 2017/03/20 23:50:13]

nit: don't have to be nice for |!cached_gcm_registration_info|

[johnme, 2017/03/30 18:36:38]

M'ok. In that case I'll also remove the niceness from GCMClientImpl::Register
(where I copied it from).

+        gcm_registration_info->sender_ids !=
+            cached_gcm_registration_info->sender_ids) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 void GCMClientImpl::Unregister(
     const linked_ptr<RegistrationInfo>& registration_info) {
   DCHECK_EQ(state_, READY);