Make Web Push use InstanceID tokens instead of GCM registrations

components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.cc

Index: components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.cc
diff --git a/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.cc b/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.cc
index b62270b187daab4f3ae08e71a890515d9bd64e06..c0db85ffb15cb2234fafc079053cfa0317168c8c 100644
--- a/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.cc
+++ b/components/gcm_driver/instance_id/fake_gcm_driver_for_instance_id.cc
@@ -17,6 +17,10 @@ namespace instance_id {
 FakeGCMDriverForInstanceID::FakeGCMDriverForInstanceID() {
 }
 
+FakeGCMDriverForInstanceID::FakeGCMDriverForInstanceID(
+    const scoped_refptr<base::SequencedTaskRunner>& blocking_task_runner)
+    : FakeGCMDriver(blocking_task_runner) {}
+
 FakeGCMDriverForInstanceID::~FakeGCMDriverForInstanceID() {
 }
 
@@ -67,6 +71,9 @@ void FakeGCMDriverForInstanceID::GetToken(
     tokens_[key] = token;
   }
 
+  last_registered_app_id_ = app_id;
+  last_registered_authorized_entity_ = authorized_entity;
+
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(callback, token, gcm::GCMClient::SUCCESS));
 }