[Push API] Fix flaky PushEventNotificationWithoutEventWaitUntil

chrome/browser/push_messaging/push_messaging_service_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/push_messaging/push_messaging_service_impl.h"
 
 #include <vector>
 
 #include "base/barrier_closure.h"
 #include "base/base64url.h"
@@ skipping 377 matching lines @@
 void PushMessagingServiceImpl::DidHandleMessage(
     const std::string& app_id,
     const base::Closure& message_handled_closure) {
   auto in_flight_iterator = in_flight_message_deliveries_.find(app_id);
   DCHECK(in_flight_iterator != in_flight_message_deliveries_.end());
 
   // Remove a single in-flight delivery for |app_id|. This has to be done using
   // an iterator rather than by value, as the latter removes all entries.
   in_flight_message_deliveries_.erase(in_flight_iterator);
 
+#if BUILDFLAG(ENABLE_BACKGROUND)
+  // Reset before running callbacks below, so tests can verify keep-alive reset.
+  if (in_flight_message_deliveries_.empty())
+    in_flight_keep_alive_.reset();
+#endif
+
   message_handled_closure.Run();
 
   if (push_messaging_service_observer_)
     push_messaging_service_observer_->OnMessageHandled();
-
-#if BUILDFLAG(ENABLE_BACKGROUND)
-  if (in_flight_message_deliveries_.empty())
-    in_flight_keep_alive_.reset();
-#endif
 }
 
 void PushMessagingServiceImpl::SetMessageCallbackForTesting(
     const base::Closure& callback) {
   message_callback_for_testing_ = callback;
 }
 
 // Other gcm::GCMAppHandler methods --------------------------------------------
 
 void PushMessagingServiceImpl::OnMessagesDeleted(const std::string& app_id) {
@@ skipping 571 matching lines @@
 }
 
 instance_id::InstanceIDDriver* PushMessagingServiceImpl::GetInstanceIDDriver()
     const {
   instance_id::InstanceIDProfileService* instance_id_profile_service =
       instance_id::InstanceIDProfileServiceFactory::GetForProfile(profile_);
   CHECK(instance_id_profile_service);
   CHECK(instance_id_profile_service->driver());
   return instance_id_profile_service->driver();
 }