Adds MediaStreamSource, MediaStreamAudioSource and MediaStreamVideoCaptureDeviceSource

content/renderer/media/media_stream_video_capture_device_source.cc

+// 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.
+
+#include "content/renderer/media/media_stream_video_capture_device_source.h"
+
+#include "base/bind.h"
+#include "base/debug/trace_event.h"
+#include "content/renderer/media/rtc_video_capturer.h"
+
+namespace content {
+
+MediaStreamVideoCaptureDeviceSource::MediaStreamVideoCaptureDeviceSource(
+    const StreamDeviceInfo& device_info,
+    const SourceStopCallback& stop_callback) {
+  SetDeviceInfo(device_info);
+  SetStopCallback(stop_callback);
+}
+
+MediaStreamVideoCaptureDeviceSource::~MediaStreamVideoCaptureDeviceSource() {
+}
+
+void MediaStreamVideoCaptureDeviceSource::Init(
+    const blink::WebMediaConstraints& constraints,
+    MediaStreamDependencyFactory* dependency_factory) {
+  DCHECK(!GetAdapter());
+  cricket::VideoCapturer* capturer =
+      dependency_factory->CreateVideoCapturer(device_info());

[Ronghua Wu (Left Chromium), 2014/01/10 20:01:08]

Instead of reusing the RtcVideoCapturer, I think we should use this one to
replace RtcVideoCapturer. Basically taking the frames from
RtcVideoCaptureDelegate, deliver it to the base class (MediaStreamVideoSource)
via the DeliverVideoFrame interface. The point of MediaStreamVideoSource is to
hide the libjingle detail, i.e. we don't need to implement
cricket::VideoCapturer.

Something like:

class MediaStreamVideoCaptureDeviceSource : public MediaStreamVideoSource {
   ...
   delegate_(new RtcVideoCaptureDelegate(id, vc_manager)),
   ...
  delegate_->StartCapture(
      request,
      base::Bind(&MediaStreamVideoCaptureDeviceSource::OnFrameCaptured,
base::Unretained(this)),
      base::Bind(&MediaStreamVideoCaptureDeviceSource::OnStateChange,
base::Unretained(this)));
  ...


  void RtcVideoCapturer::OnFrameCaptured(...) {
    ...
    DeliverVideoFrame(frame);
  }
}

[perkj_chrome, 2014/01/12 19:34:38]

Yes - that is what I plan to do in the future. But since all contstraints
parsing is done videosource.cc it will be fairly large cl. So I did this as an
intermediate step. 

+  SetAdapter(
+      dependency_factory->CreateLocalVideoSource(capturer, constraints));
+}
+
+void MediaStreamVideoCaptureDeviceSource::ApplyConstraints(
+    const blink::WebMediaStreamTrack& track,
+    const blink::WebMediaConstraints& constraints,
+    const ConstraintsCallback& callback) {
+
+  // DO NOT SUBMIT. Need to check that the camera was started successfully.
+  // Also - Check for mismatch if new constraints are set that don't match with
+  // the initial constraints.
+  callback.Run(this, true);
+}
+
+}  // namespace content