image_decoder: Delay shutdown on idle

services/image_decoder/image_decoder_service.cc

 // Copyright 2016 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 "services/image_decoder/image_decoder_service.h"
 
 #include "base/macros.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "services/image_decoder/image_decoder_impl.h"
 #include "services/image_decoder/public/interfaces/image_decoder.mojom.h"
 #include "services/service_manager/public/cpp/interface_registry.h"
 #include "services/service_manager/public/cpp/service_context.h"
 
 namespace image_decoder {
 
 namespace {
 
 void OnConnectionLost(std::unique_ptr<service_manager::ServiceContextRef> ref) {
   // No-op. This merely takes ownership of |ref| so it can be destroyed when
   // this function is invoked.
 }
 
 void OnImageDecoderRequest(
     service_manager::ServiceContextRefFactory* ref_factory,
     mojom::ImageDecoderRequest request) {
   mojo::MakeStrongBinding(
       base::MakeUnique<ImageDecoderImpl>(ref_factory->CreateRef()),
       std::move(request));
 }
 
 }  // namespace
 
-ImageDecoderService::ImageDecoderService() = default;
+ImageDecoderService::ImageDecoderService() : weak_factory_(this) {}
 
 ImageDecoderService::~ImageDecoderService() = default;
 
 // static
 std::unique_ptr<service_manager::Service> ImageDecoderService::Create() {
   return base::MakeUnique<ImageDecoderService>();
 }
 
 void ImageDecoderService::OnStart() {
   ref_factory_.reset(new service_manager::ServiceContextRefFactory(
-      base::Bind(&service_manager::ServiceContext::RequestQuit,
-                 base::Unretained(context()))));
+      base::Bind(&ImageDecoderService::MaybeRequestQuitDelayed,
+                 base::Unretained(this))));
 }
 
 bool ImageDecoderService::OnConnect(
     const service_manager::ServiceInfo& remote_info,
     service_manager::InterfaceRegistry* registry) {
   // Add a reference to the service and tie it to the lifetime of the
   // InterfaceRegistry's connection.
   std::unique_ptr<service_manager::ServiceContextRef> connection_ref =
       ref_factory_->CreateRef();
   registry->AddConnectionLostClosure(
       base::Bind(&OnConnectionLost, base::Passed(&connection_ref)));
   registry->AddInterface(
       base::Bind(&OnImageDecoderRequest, ref_factory_.get()));
   return true;
 }
 
 bool ImageDecoderService::OnStop() {
   return true;
 }
 
+void ImageDecoderService::MaybeRequestQuitDelayed() {
+  base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&ImageDecoderService::MaybeRequestQuit,
+                 weak_factory_.GetWeakPtr()),
+      base::TimeDelta::FromSeconds(5));
+}
+
+void ImageDecoderService::MaybeRequestQuit() {
+  DCHECK(ref_factory_);
+  if (ref_factory_->HasNoRefs())
+    context()->RequestQuit();
+}
+
 }  // namespace image_decoder