MediaStream audio object graph untangling and clean-ups.

content/public/renderer/media_stream_api.h

 // Copyright 2015 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_PUBLIC_RENDERER_MEDIA_STREAM_API_H_
 #define CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_API_H_
 
 #include "content/common/content_export.h"
 #include "media/base/audio_capturer_source.h"
+#include "media/base/channel_layout.h"
 #include "media/base/video_capturer_source.h"
 
 namespace blink {
 class WebMediaStream;
 }
 
-namespace media {
-class AudioParameters;
-}
-
 namespace content {
 // These methods create a WebMediaStreamSource + MediaStreamSource pair with the
 // provided audio or video capturer source. A new WebMediaStreamTrack +
-// MediaStreamTrack pair is created, holding the previous MediaStreamSource, and
-// is plugged into the stream identified by |media_stream_url| (or passed as
-// |web_stream|).
+// MediaStreamTrack pair is created, connected to the source and is plugged into
+// the WebMediaStream (|web_media_stream|).
 // |is_remote| should be true if the source of the data is not a local device.
 // |is_readonly| should be true if the format of the data cannot be changed by
 //     MediaTrackConstraints.
 CONTENT_EXPORT bool AddVideoTrackToMediaStream(
-    scoped_ptr<media::VideoCapturerSource> source,
+    scoped_ptr<media::VideoCapturerSource> video_source,
     bool is_remote,
     bool is_readonly,
-    const std::string& media_stream_url);
-CONTENT_EXPORT bool AddVideoTrackToMediaStream(
-    scoped_ptr<media::VideoCapturerSource> source,
+    blink::WebMediaStream* web_media_stream);
+
+// |sample_rate|, |channel_layout|, and |frames_per_buffer| specify the audio
+// parameters of the track. Generally, these should match the |audio_source| so
+// that it does not have to perform unnecessary sample rate conversion or
+// channel mixing.
+CONTENT_EXPORT bool AddAudioTrackToMediaStream(
+    scoped_refptr<media::AudioCapturerSource> audio_source,
+    int sample_rate,
+    media::ChannelLayout channel_layout,
+    int frames_per_buffer,
     bool is_remote,
     bool is_readonly,
-    blink::WebMediaStream* web_stream);
-
-CONTENT_EXPORT bool AddAudioTrackToMediaStream(
-    const scoped_refptr<media::AudioCapturerSource>& source,
-    const media::AudioParameters& params,
-    bool is_remote,
-    bool is_readonly,
-    const std::string& media_stream_url);
-CONTENT_EXPORT bool AddAudioTrackToMediaStream(
-    const scoped_refptr<media::AudioCapturerSource>& source,
-    bool is_remote,
-    bool is_readonly,
-    blink::WebMediaStream* web_stream);
+    blink::WebMediaStream* web_media_stream);
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_API_H_