Reland "Bind StreamFactory in audio service."

This is a reland of 21f2ef4c

Per offline discussion, this code is fine.

Original change's description:
> Bind StreamFactory in audio service.
>
> Bug: 803102
> Change-Id: I4d8cb112445095045c492488f7c3b8d9853b6c23
> Reviewed-on: https://chromium-review.googlesource.com/1004634
> Commit-Queue: Max Morin <maxmorin@chromium.org>
> Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
> Reviewed-by: Olga Sharonova <olka@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#549481}

Tbr: 
Bug: 803102
Change-Id: I3b14b633dd1419eae570d2b9ab411fc8732fad4c
Reviewed-on: https://chromium-review.googlesource.com/1005080Reviewed-by: Max Morin <maxmorin@chromium.org>
Commit-Queue: Max Morin <maxmorin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#549504}

services/audio/BUILD.gn

@@ -74,6 +74,7 @@ source_set("tests") {
     "input_stream_unittest.cc",
     "output_controller_unittest.cc",
     "output_stream_unittest.cc",
+    "stream_factory_unittest.cc",
     "sync_reader_unittest.cc",
     "test/audio_system_to_service_adapter_test.cc",
     "test/debug_recording_session_unittest.cc",

services/audio/manifest.json

@@ -6,7 +6,8 @@
     "service_manager:connector": {
       "provides": {
         "info": [ "audio::mojom::SystemInfo" ],
-        "debug_recording": [ "audio::mojom::DebugRecording" ]
+        "debug_recording": [ "audio::mojom::DebugRecording" ],
+        "stream_factory": [ "audio::mojom::StreamFactory" ]
       },
       "requires": {
         "service_manager": [ "service_manager:all_users" ]

services/audio/public/mojom/stream_factory.mojom

@@ -10,6 +10,9 @@ import "mojo/public/mojom/base/unguessable_token.mojom";
 // (like the browser process) to create streams. Note that while the factory
 // interface itself is only for trusted clients, the created streams and data
 // pipes may be forwarded to untrusted clients.
+//
+// The client must keep the connection to the factory while streams are
+// running.
 // TODO(803102): Add other stream creation functionality to this interface.
 interface StreamFactory {
   // Creates an AudioOutputStream and returns the AudioDataPipe it reads data

services/audio/service.cc

@@ -90,6 +90,14 @@ void Service::BindDebugRecordingRequest(mojom::DebugRecordingRequest request) {
       ref_factory_->CreateRef());
 }
 
+void Service::BindStreamFactoryRequest(mojom::StreamFactoryRequest request) {
+  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
+  DCHECK(ref_factory_);
+  if (!stream_factory_)
+    stream_factory_.emplace(audio_manager_accessor_->GetAudioManager());
+  stream_factory_->Bind(std::move(request), ref_factory_->CreateRef());
+}
+
 void Service::MaybeRequestQuitDelayed() {
   DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
   if (quit_timeout_ <= base::TimeDelta())

services/audio/service.h

@@ -10,10 +10,13 @@
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/optional.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "services/audio/public/mojom/debug_recording.mojom.h"
+#include "services/audio/public/mojom/stream_factory.mojom.h"
 #include "services/audio/public/mojom/system_info.mojom.h"
+#include "services/audio/stream_factory.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
 #include "services/service_manager/public/cpp/service.h"
 
@@ -64,6 +67,7 @@ class Service : public service_manager::Service {
  private:
   void BindSystemInfoRequest(mojom::SystemInfoRequest request);
   void BindDebugRecordingRequest(mojom::DebugRecordingRequest request);
+  void BindStreamFactoryRequest(mojom::StreamFactoryRequest request);
 
   void MaybeRequestQuitDelayed();
   void MaybeRequestQuit();
@@ -81,6 +85,7 @@ class Service : public service_manager::Service {
   std::unique_ptr<AudioManagerAccessor> audio_manager_accessor_;
   std::unique_ptr<SystemInfo> system_info_;
   std::unique_ptr<DebugRecording> debug_recording_;
+  base::Optional<StreamFactory> stream_factory_;
 
   service_manager::BinderRegistry registry_;
 

services/audio/stream_factory.cc

@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "services/audio/output_stream.h"
+#include "services/service_manager/public/cpp/service_context_ref.h"
 
 namespace audio {
 
@@ -17,9 +18,11 @@ StreamFactory::~StreamFactory() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(owning_sequence_);
 }
 
-void StreamFactory::BindRequest(mojom::StreamFactoryRequest request) {
+void StreamFactory::Bind(
+    mojom::StreamFactoryRequest request,
+    std::unique_ptr<service_manager::ServiceContextRef> context_ref) {
   DCHECK_CALLED_ON_VALID_SEQUENCE(owning_sequence_);
-  bindings_.AddBinding(this, std::move(request));
+  bindings_.AddBinding(this, std::move(request), std::move(context_ref));
 }
 
 void StreamFactory::CreateOutputStream(

services/audio/stream_factory.h

@@ -27,6 +27,10 @@ class AudioManager;
 class AudioParameters;
 }  // namespace media
 
+namespace service_manager {
+class ServiceContextRef;
+}
+
 namespace audio {
 
 class OutputStream;
@@ -40,7 +44,8 @@ class StreamFactory final : public mojom::StreamFactory {
   explicit StreamFactory(media::AudioManager* audio_manager);
   ~StreamFactory() final;
 
-  void BindRequest(mojom::StreamFactoryRequest request);
+  void Bind(mojom::StreamFactoryRequest request,
+            std::unique_ptr<service_manager::ServiceContextRef> context_ref);
 
   // StreamFactory implementation.
   void CreateOutputStream(
@@ -63,7 +68,10 @@ class StreamFactory final : public mojom::StreamFactory {
 
   media::AudioManager* const audio_manager_;
 
-  mojo::BindingSet<mojom::StreamFactory> bindings_;
+  mojo::BindingSet<mojom::StreamFactory,
+                   std::unique_ptr<service_manager::ServiceContextRef>>
+      bindings_;
+
   OutputStreamSet output_streams_;
 
   DISALLOW_COPY_AND_ASSIGN(StreamFactory);

services/audio/stream_factory_unittest.cc

+// Copyright 2018 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/audio/stream_factory.h"
+
+#include <memory>
+
+#include "base/test/scoped_task_environment.h"
+#include "media/audio/mock_audio_manager.h"
+#include "media/audio/test_audio_thread.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "services/audio/public/mojom/stream_factory.mojom.h"
+#include "services/service_manager/public/cpp/service_context_ref.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace audio {
+
+// Stream creation is tested as part of the stream unit tests.
+TEST(AudioServiceStreamFactoryTest, TakesServiceRef) {
+  base::test::ScopedTaskEnvironment env;
+  service_manager::ServiceContextRefFactory ref_factory{base::DoNothing()};
+  media::MockAudioManager audio_manager(
+      std::make_unique<media::TestAudioThread>());
+
+  StreamFactory factory(&audio_manager);
+
+  mojom::StreamFactoryPtr factory_ptr;
+
+  factory.Bind(mojo::MakeRequest(&factory_ptr), ref_factory.CreateRef());
+  EXPECT_FALSE(ref_factory.HasNoRefs());
+  factory_ptr.reset();
+  env.RunUntilIdle();
+  EXPECT_TRUE(ref_factory.HasNoRefs());
+  audio_manager.Shutdown();
+}
+
+}  // namespace audio