[WIP] Move media/capture to device/capture

media/capture/content/thread_safe_capture_oracle.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 MEDIA_CAPTURE_CONTENT_THREAD_SAFE_CAPTURE_ORACLE_H_
-#define MEDIA_CAPTURE_CONTENT_THREAD_SAFE_CAPTURE_ORACLE_H_
-
-#include <memory>
-#include <string>
-
-#include "base/memory/ref_counted.h"
-#include "media/base/video_frame.h"
-#include "media/capture/capture_export.h"
-#include "media/capture/content/video_capture_oracle.h"
-#include "media/capture/video/video_capture_device.h"
-
-namespace tracked_objects {
-class Location;
-}  // namespace tracked_objects
-
-namespace media {
-
-struct VideoCaptureParams;
-class VideoFrame;
-
-// Thread-safe, refcounted proxy to the VideoCaptureOracle.  This proxy wraps
-// the VideoCaptureOracle, which decides which frames to capture, and a
-// VideoCaptureDevice::Client, which allocates and receives the captured
-// frames, in a lock to synchronize state between the two.
-class CAPTURE_EXPORT ThreadSafeCaptureOracle
-    : public base::RefCountedThreadSafe<ThreadSafeCaptureOracle> {
- public:
-  ThreadSafeCaptureOracle(std::unique_ptr<VideoCaptureDevice::Client> client,
-                          const VideoCaptureParams& params,
-                          bool enable_auto_throttling);
-
-  // Called when a captured frame is available or an error has occurred.
-  // If |success| is true then |frame| is valid and |timestamp| indicates when
-  // the frame was painted.
-  // If |success| is false, all other parameters are invalid.
-  typedef base::Callback<void(const scoped_refptr<VideoFrame>& frame,
-                              base::TimeTicks timestamp,
-                              bool success)> CaptureFrameCallback;
-
-  // Record a change |event| along with its |damage_rect| and |event_time|, and
-  // then make a decision whether to proceed with capture. The decision is based
-  // on recent event history, capture activity, and the availability of
-  // resources.
-  //
-  // If this method returns false, the caller should take no further action.
-  // Otherwise, |storage| is set to the destination for the video frame capture
-  // and the caller should initiate capture.  Then, once the video frame has
-  // been populated with its content, or if capture failed, the |callback|
-  // should be run.
-  bool ObserveEventAndDecideCapture(VideoCaptureOracle::Event event,
-                                    const gfx::Rect& damage_rect,
-                                    base::TimeTicks event_time,
-                                    scoped_refptr<VideoFrame>* storage,
-                                    CaptureFrameCallback* callback);
-
-  // Attempt to re-send the last frame to the VideoCaptureDevice::Client.
-  // Returns true if successful. This can fail if the last frame is no longer
-  // available in the buffer pool, or if the VideoCaptureOracle decides to
-  // reject the "passive" refresh.
-  bool AttemptPassiveRefresh();
-
-  base::TimeDelta min_capture_period() const {
-    return oracle_.min_capture_period();
-  }
-
-  base::TimeTicks last_time_animation_was_detected() const {
-    return oracle_.last_time_animation_was_detected();
-  }
-
-  gfx::Size max_frame_size() const {
-    return params_.requested_format.frame_size;
-  }
-
-  // Returns the current capture resolution.
-  gfx::Size GetCaptureSize() const;
-
-  // Updates capture resolution based on the supplied source size and the
-  // maximum frame size.
-  void UpdateCaptureSize(const gfx::Size& source_size);
-
-  // Stop new captures from happening (but doesn't forget the client).
-  void Stop();
-
-  // Signal an error to the client.
-  void ReportError(const tracked_objects::Location& from_here,
-                   const std::string& reason);
-
- private:
-  friend class base::RefCountedThreadSafe<ThreadSafeCaptureOracle>;
-  virtual ~ThreadSafeCaptureOracle();
-
-  // Callback invoked on completion of all captures.
-  void DidCaptureFrame(
-      int frame_number,
-      std::unique_ptr<VideoCaptureDevice::Client::Buffer> buffer,
-      base::TimeTicks capture_begin_time,
-      base::TimeDelta estimated_frame_duration,
-      const scoped_refptr<VideoFrame>& frame,
-      base::TimeTicks reference_time,
-      bool success);
-
-  // Callback invoked once all consumers have finished with a delivered video
-  // frame.  Consumer feedback signals are scanned from the frame's |metadata|.
-  void DidConsumeFrame(int frame_number,
-                       const media::VideoFrameMetadata* metadata);
-
-  // Protects everything below it.
-  mutable base::Lock lock_;
-
-  // Recipient of our capture activity.
-  std::unique_ptr<VideoCaptureDevice::Client> client_;
-
-  // Makes the decision to capture a frame.
-  VideoCaptureOracle oracle_;
-
-  // The video capture parameters used to construct the oracle proxy.
-  const VideoCaptureParams params_;
-};
-
-}  // namespace media
-
-#endif  // MEDIA_CAPTURE_CONTENT_THREAD_SAFE_CAPTURE_ORACLE_H_