Add mojo interface+impl creation of audio streams.

content/browser/renderer_host/media/audio_output_stream_factory_context_impl.h

Index: content/browser/renderer_host/media/audio_output_stream_factory_context_impl.h
diff --git a/content/browser/renderer_host/media/audio_output_stream_factory_context_impl.h b/content/browser/renderer_host/media/audio_output_stream_factory_context_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..adb3131c4fef6bc16b1c8b5635913ed51a484a20
--- /dev/null
+++ b/content/browser/renderer_host/media/audio_output_stream_factory_context_impl.h
@@ -0,0 +1,73 @@
+// 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_AUDIO_OUTPUT_STREAM_FACTORY_CONTEXT_IMPL_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_OUTPUT_STREAM_FACTORY_CONTEXT_IMPL_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "content/browser/renderer_host/media/audio_output_stream_factory_context.h"
+#include "mojo/public/cpp/bindings/interface_request.h"
+
+namespace media {
+class AudioSystem;
+}  // namespace media
+
+namespace content {
+
+class MediaStreamManager;
+
+// In addition to being an AudioOutputStreamFactoryContext, this class also
+// handles requests for mojom::RendererAudioOutputStreamFactory instances.

[o1ka, 2017/03/21 16:20:17]

This sounds confusing, since "request" is also a Mojo term. "Serves as a factory
for.." maybe?

[Max Morin, 2017/03/22 13:18:29]

"request" means mojo request.

[o1ka, 2017/03/23 09:39:43]

Ah, now I see it when you clarified the usage.

+class CONTENT_EXPORT AudioOutputStreamFactoryContextImpl
+    : public AudioOutputStreamFactoryContext {
+ public:
+  AudioOutputStreamFactoryContextImpl(int render_process_id,
+                                      media::AudioSystem* audio_system,
+                                      MediaStreamManager* media_stream_manager,
+                                      const std::string& salt);
+
+  ~AudioOutputStreamFactoryContextImpl() override;
+
+  void CreateFactory(

[o1ka, 2017/03/21 16:20:17]

Could you add a comment on its usage?

[Max Morin, 2017/03/22 13:18:29]

Done.

+      int frame_host_id,
+      mojo::InterfaceRequest<mojom::RendererAudioOutputStreamFactory> request);
+
+  // AudioOutputStreamFactoryContext impl:

[o1ka, 2017/03/21 16:20:17]

implementation.

[Max Morin, 2017/03/22 13:18:29]

Done.

+  int GetRenderProcessId() 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;
+
+  const std::string& GetSalt() 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;
+
+  void OnFactoryFinished(
+      mojom::RendererAudioOutputStreamFactory* factory) override;
+
+ private:
+  const int render_process_id_;
+  media::AudioSystem* const audio_system_;
+  MediaStreamManager* const media_stream_manager_;
+  const std::string salt_;
+  const AudioOutputAuthorizationHandler authorization_handler_;
+  int next_stream_id_ = 0;
+  std::vector<std::unique_ptr<mojom::RendererAudioOutputStreamFactory>>
+      factories_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_OUTPUT_STREAM_FACTORY_CONTEXT_IMPL_H_