[FCM] Enable lazy mode for invalidations

Supporting lazy subscriptions modes for FCM subscription has been fully
implemented.

This CL enables the lazy mode for invalidations.

Bug: 882887
Change-Id: I47ab65b4895fed35dfdfd291ce155dc0928a14d5
Reviewed-on: https://chromium-review.googlesource.com/c/1347359Reviewed-by: Tatiana Gornak <melandory@chromium.org>
Commit-Queue: Mohamed Amir Yosef <mamir@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610564}

components/invalidation/impl/fcm_network_handler.cc

@@ -90,12 +90,10 @@ void FCMNetworkHandler::StartListening() {
   // Being the listener is pre-requirement for token operations.
   gcm_driver_->AddAppHandler(kInvalidationsAppId, this);
 
-  // TODO(https://crbug.com/882887): Switch to a lazy subscription when they are
-  // supported by the GCM driver.
   instance_id_driver_->GetInstanceID(kInvalidationsAppId)
       ->GetToken(kInvalidationGCMSenderId, kGCMScope,
                  /*options=*/std::map<std::string, std::string>(),
-                 /*is_lazy=*/false,
+                 /*is_lazy=*/true,
                  base::BindRepeating(&FCMNetworkHandler::DidRetrieveToken,
                                      weak_ptr_factory_.GetWeakPtr()));
 }
@@ -145,12 +143,10 @@ void FCMNetworkHandler::ScheduleNextTokenValidation() {
 void FCMNetworkHandler::StartTokenValidation() {
   DCHECK(IsListening());
 
-  // TODO(https://crbug.com/882887): Switch to a lazy subscription when they are
-  // supported by the GCM driver.
   instance_id_driver_->GetInstanceID(kInvalidationsAppId)
       ->GetToken(kInvalidationGCMSenderId, kGCMScope,
                  std::map<std::string, std::string>(),
-                 /*is_lazy=*/false,
+                 /*is_lazy=*/true,
                  base::Bind(&FCMNetworkHandler::DidReceiveTokenForValidation,
                             weak_ptr_factory_.GetWeakPtr()));
 }