Adds MediaStreamSource, MediaStreamAudioSource and MediaStreamVideoCaptureDeviceSource

content/renderer/media/media_stream_source.h

+// Copyright 2014 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_MEDIA_MEDIA_STREAM_SOURCE_H_
+#define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_SOURCE_H_
+
+#include "base/callback.h"
+#include "base/compiler_specific.h"
+#include "content/common/content_export.h"
+#include "content/common/media/media_stream_options.h"
+#include "third_party/WebKit/public/platform/WebMediaStreamSource.h"
+
+namespace blink {
+class WebMediaStreamTrack;
+}  // namespace blink
+
+namespace content {
+
+class CONTENT_EXPORT MediaStreamSource
+    : NON_EXPORTED_BASE(public blink::WebMediaStreamSource::ExtraData) {
+ public:
+  typedef base::Callback<void(const blink::WebMediaStreamSource& source)>
+      SourceStoppedCallback;
+
+  typedef base::Callback<void(MediaStreamSource* source,
+                              bool success)> ConstraintsCallback;
+
+  MediaStreamSource();
+  virtual ~MediaStreamSource();
+
+  virtual void AddTrack(const blink::WebMediaStreamTrack& track,

[no longer working on chromium, 2014/01/17 14:51:51]

so the constraints is back to AddTrack?

[perkj_chrome, 2014/01/19 15:52:39]

Yupp :->

+                        const blink::WebMediaConstraints& constraints,
+                        const ConstraintsCallback& callback) = 0;
+  virtual void RemoveTrack(const blink::WebMediaStreamTrack& track) = 0;
+
+  // Return device information about a source that has been created by a

[no longer working on chromium, 2014/01/17 14:51:51]

nit, Returns

[perkj_chrome, 2014/01/19 15:52:39]

Done.

+  // JavaScript call to GetUserMedia. F.E a camera or microphone.
+  const StreamDeviceInfo& device_info() const {
+    return device_info_;
+  }
+
+  // Stops the source (by calling DoStopSource()). This sets the
+  // WebMediaStreamSource::readyState to ended, triggers the |stop_callback_|
+  // if set. All pointers to this object are invalid after calling this.
+  void StopSource();
+
+  void ResetSourceStoppedCallback() {
+    DCHECK(!stop_callback_.is_null());
+    stop_callback_.Reset();
+  }
+
+ protected:
+  // Called when StopSource is called. It allows derived classes to implement
+  // its  own Stop method.
+  virtual void DoStopSource() = 0;
+
+  // Set device information about a source that has been created by a
+  // JavaScript call to GetUserMedia. F.E a camera or microphone.
+  void SetDeviceInfo(const StreamDeviceInfo& device_info) {

[no longer working on chromium, 2014/01/17 14:51:51]

The source should be created with a specific device_info, can we pass the
device_info via the constructor and remove this method?

[perkj_chrome, 2014/01/19 15:52:39]

There are other types of sources that don't need the device info. Such WebAudio
or the VideoSource that Ronghua is trying to implement for NaCl. So I prefer to
not have it in the constructor.

+    device_info_ = device_info;
+  }
+
+  // Set a callback that will be triggered when StopSource is called.
+  void SetStopCallback(const SourceStoppedCallback& stop_callback) {

[no longer working on chromium, 2014/01/17 14:51:51]

same here, pass the stop_callback via the constructor, if possible.

[perkj_chrome, 2014/01/19 15:52:39]

dito. Not all sources need the stop callback I think.

+    DCHECK(stop_callback_.is_null());
+    stop_callback_ = stop_callback;
+  }
+
+ private:
+  StreamDeviceInfo device_info_;
+  SourceStoppedCallback stop_callback_;

[no longer working on chromium, 2014/01/17 14:51:51]

and make those members const if they can be passed in the constructor.

[perkj_chrome, 2014/01/19 15:52:39]

See response above.

+
+  DISALLOW_COPY_AND_ASSIGN(MediaStreamSource);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_SOURCE_H_