Add mojo interface+impl creation of audio streams.

content/browser/renderer_host/media/renderer_audio_output_stream_factory_context_impl.h

Index: content/browser/renderer_host/media/renderer_audio_output_stream_factory_context_impl.h
diff --git a/content/browser/renderer_host/media/renderer_audio_output_stream_factory_context_impl.h b/content/browser/renderer_host/media/renderer_audio_output_stream_factory_context_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..cab74c7bdaf97a215c18877241c7dea5563d6196
--- /dev/null
+++ b/content/browser/renderer_host/media/renderer_audio_output_stream_factory_context_impl.h
@@ -0,0 +1,99 @@
+// Copyright 2017 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_BROWSER_RENDERER_HOST_MEDIA_RENDERER_AUDIO_OUTPUT_STREAM_FACTORY_CONTEXT_IMPL_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_RENDERER_AUDIO_OUTPUT_STREAM_FACTORY_CONTEXT_IMPL_H_
+
+#include <memory>
+#include <string>
+
+#include "content/browser/renderer_host/media/renderer_audio_output_stream_factory_context.h"
+#include "content/common/media/renderer_audio_output_stream_factory.mojom.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+#include "mojo/public/cpp/bindings/strong_binding_set.h"
+
+namespace media {
+class AudioSystem;
+}  // namespace media
+
+namespace content {
+
+class MediaStreamManager;
+
+// In addition to being a RendererAudioOutputStreamFactoryContext, this class
+// also handles requests for mojom::RendererAudioOutputStreamFactory instances.
+//
+// Ownership diagram for stream IPC classes (excluding interfaces):
+// RendererAudioOutputStreamFactoryContext
+//                 ^
+//                 | owns (at most one per render frame in the process).
+//                 |
+// RenderFrameAudioOutputStreamFactory
+//                 ^
+//                 | owns (one per stream for the frame).
+//                 |
+// media::MojoAudioOutputStreamProvider
+//                 ^
+//                 | owns (one).
+//                 |
+// media::MojoAudioOutputStream

[o1ka, 2017/03/29 08:13:48]

Great, thanks! (an arrow is a bit confusing though since it looks more like
inheritance)

[Max Morin, 2017/03/30 12:48:50]

Hopefully, the text clears it up :).

+
+class CONTENT_EXPORT RendererAudioOutputStreamFactoryContextImpl
+    : public RendererAudioOutputStreamFactoryContext {
+ public:
+  RendererAudioOutputStreamFactoryContextImpl(
+      int render_process_id,
+      media::AudioSystem* audio_system,
+      MediaStreamManager* media_stream_manager,
+      const std::string& salt);
+
+  ~RendererAudioOutputStreamFactoryContextImpl() override;
+
+  // Creates a factory and binds it to the request. Intended to be registered
+  // in a RenderFrameHosts InterfaceRegistry.
+  void CreateFactory(
+      int frame_host_id,
+      mojo::InterfaceRequest<mojom::RendererAudioOutputStreamFactory> request);
+
+  // RendererAudioOutputStreamFactoryContext implementation.
+  int GetRenderProcessId() const override;
+
+  std::string GetHMACForDeviceId(
+      const url::Origin& origin,
+      const std::string& raw_device_id) const override;
+
+  void RequestDeviceAuthorization(
+      int render_frame_id,
+      int session_id,
+      const std::string& device_id,
+      const url::Origin& security_origin,
+      AuthorizationCompletedCallback cb) const override;
+
+  std::unique_ptr<media::AudioOutputDelegate> CreateDelegate(
+      const std::string& unique_device_id,
+      int render_frame_id,
+      const media::AudioParameters& params,
+      media::AudioOutputDelegate::EventHandler* handler) override;
+
+ private:
+  // Used for hashing the device_id.
+  const std::string salt_;
+  const int render_process_id_;
+  media::AudioSystem* const audio_system_;
+  MediaStreamManager* const media_stream_manager_;
+  const AudioOutputAuthorizationHandler authorization_handler_;
+
+  // All streams requires ids for logging, so we keep a count for that.
+  int next_stream_id_ = 0;
+
+  // The factories created by |this| is kept here, so that we can make sure they
+  // don't keep danging references to |this|.
+  mojo::StrongBindingSet<mojom::RendererAudioOutputStreamFactory> factories_;
+
+  DISALLOW_COPY_AND_ASSIGN(RendererAudioOutputStreamFactoryContextImpl);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_RENDERER_AUDIO_OUTPUT_STREAM_FACTORY_CONTEXT_IMPL_H_