Add a mojo implementation of AudioOutputIPC.

content/renderer/render_thread_impl.h

 // Copyright (c) 2012 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.
 
 #ifndef CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 #define CONTENT_RENDERER_RENDER_THREAD_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
+#include <map>
 #include <memory>
 #include <set>
 #include <string>
+#include <utility>
 #include <vector>
 
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "base/memory/memory_coordinator_client.h"
 #include "base/memory/memory_pressure_listener.h"
 #include "base/memory/ref_counted.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/user_metrics_action.h"
 #include "base/observer_list.h"
+#include "base/optional.h"
 #include "base/strings/string16.h"
 #include "base/threading/thread_checker.h"
 #include "base/timer/timer.h"
 #include "build/build_config.h"
 #include "components/variations/child_process_field_trial_syncer.h"
 #include "content/child/child_thread_impl.h"
 #include "content/child/memory/child_memory_coordinator_impl.h"
 #include "content/common/associated_interface_registry_impl.h"
 #include "content/common/content_export.h"
 #include "content/common/frame.mojom.h"
 #include "content/common/frame_replication_state.h"
 #include "content/common/frame_sink_provider.mojom.h"
 #include "content/common/render_frame_message_filter.mojom.h"
 #include "content/common/render_message_filter.mojom.h"
 #include "content/common/renderer.mojom.h"
 #include "content/common/storage_partition_service.mojom.h"
 #include "content/public/renderer/render_thread.h"
 #include "content/renderer/gpu/compositor_dependencies.h"
 #include "content/renderer/layout_test_dependencies.h"
+#include "content/renderer/media/audio_ipc_factory.h"
 #include "gpu/ipc/client/gpu_channel_host.h"
 #include "media/media_features.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "mojo/public/cpp/bindings/thread_safe_interface_ptr.h"
 #include "net/base/network_change_notifier.h"
 #include "third_party/WebKit/public/platform/WebConnectionType.h"
 #include "third_party/WebKit/public/platform/scheduler/renderer/renderer_scheduler.h"
 #include "third_party/WebKit/public/web/WebMemoryStatistics.h"
 #include "ui/gfx/native_widget_types.h"
@@ skipping 254 matching lines @@
   }
 
   DomStorageDispatcher* dom_storage_dispatcher() const {
     return dom_storage_dispatcher_.get();
   }
 
   AudioInputMessageFilter* audio_input_message_filter() {
     return audio_input_message_filter_.get();
   }
 
-  AudioMessageFilter* audio_message_filter() {
-    return audio_message_filter_.get();
-  }
-
   MidiMessageFilter* midi_message_filter() {
     return midi_message_filter_.get();
   }
 
 #if defined(OS_ANDROID)
   SynchronousCompositorFilter* sync_compositor_message_filter() {
     return sync_compositor_message_filter_.get();
   }
 
   scoped_refptr<StreamTextureFactory> GetStreamTexureFactory();
@@ skipping 297 matching lines @@
   // Dispatches all P2P sockets.
   scoped_refptr<P2PSocketDispatcher> p2p_socket_dispatcher_;
 
   // Used for communicating registering AEC dump consumers with the browser and
   // receving AEC dump file handles when AEC dump is enabled. An AEC dump is
   // diagnostic audio data for WebRTC stored locally when enabled by the user in
   // chrome://webrtc-internals.
   scoped_refptr<AecDumpMessageFilter> aec_dump_message_filter_;
 #endif
 
+  // Provides AudioOutputIPC objects for audio output devices. It either uses
+  // |audio_message_filter_| for this or provides MojoAudioOutputIPC objects.
+  base::Optional<AudioIPCFactory> audio_ipc_factory_;

[o1ka, 2017/05/11 10:58:41]

Would unique_ptr<> be enough for that?
And under which conditions it's uninitialized?

[Max Morin, 2017/05/11 15:31:18]

There's no need for unique_ptr, since Optional is enough :). unique_ptr is an
extra allocation, so I default to using Optional, and use unique_ptr if needed.
Added a comment about initialization.

+
   // Used on the render thread.
   std::unique_ptr<VideoCaptureImplManager> vc_manager_;
 
   std::unique_ptr<ui::ChildSharedBitmapManager> shared_bitmap_manager_;
 
   // The count of RenderWidgets running through this thread.
   int widget_count_;
 
   // The count of hidden RenderWidgets running through this thread.
   int hidden_widget_count_;
@@ skipping 147 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(RenderThreadImpl);
 };
 
 #if defined(COMPILER_MSVC)
 #pragma warning(pop)
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_THREAD_IMPL_H_