Revert of Refactor video capturing code in the render process

media/video/capture/video_capture.h

+// Copyright (c) 2012 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.
+//
+// This file contains abstract classes used for media filter to handle video
+// capture devices.
+
+#ifndef MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_H_
+#define MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_H_
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/time/time.h"
+#include "media/base/media_export.h"
+#include "media/video/capture/video_capture_types.h"
+
+namespace media {
+
+class VideoFrame;
+
+class MEDIA_EXPORT VideoCapture {
+ public:
+  // TODO(wjia): add error codes.
+  // TODO(wjia): support weak ptr.
+  // Callbacks provided by client for notification of events.
+  class MEDIA_EXPORT EventHandler {
+   public:
+    // Notify client that video capture has been started.
+    virtual void OnStarted(VideoCapture* capture) = 0;
+
+    // Notify client that video capture has been stopped.
+    virtual void OnStopped(VideoCapture* capture) = 0;
+
+    // Notify client that video capture has been paused.
+    virtual void OnPaused(VideoCapture* capture) = 0;
+
+    // Notify client that video capture has hit some error |error_code|.
+    virtual void OnError(VideoCapture* capture, int error_code) = 0;
+
+    // Notify client that the client has been removed and no more calls will be
+    // received.
+    virtual void OnRemoved(VideoCapture* capture) = 0;
+
+    // Notify client that a buffer is available.
+    virtual void OnFrameReady(
+        VideoCapture* capture,
+        const scoped_refptr<media::VideoFrame>& frame) = 0;
+
+   protected:
+    virtual ~EventHandler() {}
+  };
+
+  typedef base::Callback<void(const media::VideoCaptureFormats&)>
+      DeviceFormatsCallback;
+
+  typedef base::Callback<void(const media::VideoCaptureFormats&)>
+      DeviceFormatsInUseCallback;
+
+  VideoCapture() {}
+
+  // Request video capture to start capturing with |params|.
+  // Also register |handler| with video capture for event handling.
+  // |handler| must remain valid until it has received |OnRemoved()|.
+  virtual void StartCapture(EventHandler* handler,
+                            const VideoCaptureParams& params) = 0;
+
+  // Request video capture to stop capturing for client |handler|.
+  // |handler| must remain valid until it has received |OnRemoved()|.
+  virtual void StopCapture(EventHandler* handler) = 0;
+
+  virtual bool CaptureStarted() = 0;
+  virtual int CaptureFrameRate() = 0;
+
+  // Request the device capture supported formats. This method can be called
+  // before startCapture() and/or after stopCapture() so a |callback| is used
+  // instead of replying via EventHandler.
+  virtual void GetDeviceSupportedFormats(
+      const DeviceFormatsCallback& callback) = 0;
+
+  // Request the device capture in-use format(s), possibly by other user(s) in
+  // other renderer(s). If there is no format in use, the vector returned in
+  // the callback will be empty.
+  virtual void GetDeviceFormatsInUse(
+      const DeviceFormatsInUseCallback& callback) = 0;
+
+ protected:
+  virtual ~VideoCapture() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VideoCapture);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_VIDEO_CAPTURE_VIDEO_CAPTURE_H_