Move ContentVideoCaptureDeviceCore from src/content to src/media

media/capture/screen_capture_device_core.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_SCREEN_CAPTURE_DEVICE_CORE_H_
+#define MEDIA_CAPTURE_SCREEN_CAPTURE_DEVICE_CORE_H_
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "media/base/media_export.h"
+#include "media/capture/thread_safe_capture_oracle.h"
+#include "media/video/capture/video_capture_device.h"
+
+namespace media {
+
+class VideoCaptureParams;
+
+class ThreadSafeCaptureOracle;
+
+// Keeps track of the video capture source frames and executes copying.
+class VideoCaptureMachine {
+ public:
+  VideoCaptureMachine() {}
+  virtual ~VideoCaptureMachine() {}
+
+  // Starts capturing.
+  // |callback| is invoked with true if succeeded. Otherwise, with false.
+  virtual void Start(const scoped_refptr<ThreadSafeCaptureOracle>& oracle_proxy,
+                     const VideoCaptureParams& params,
+                     const base::Callback<void(bool)> callback) = 0;
+
+  // Stops capturing.
+  // |callback| is invoked after the capturing has stopped.
+  virtual void Stop(const base::Closure& callback) = 0;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VideoCaptureMachine);
+};
+
+// The "meat" of a content video capturer.
+//
+// Separating this from the "shell classes" WebContentsVideoCaptureDevice and
+// DesktopCaptureDeviceAura allows safe destruction without needing to block any
+// threads, as well as code sharing.
+//
+// ScreenCaptureDeviceCore manages a simple state machine and the pipeline
+// (see notes at top of this file).  It times the start of successive captures
+// and facilitates the processing of each through the stages of the
+// pipeline.
+class MEDIA_EXPORT ScreenCaptureDeviceCore
+    : public base::SupportsWeakPtr<ScreenCaptureDeviceCore> {
+ public:
+  ScreenCaptureDeviceCore(
+      scoped_ptr<VideoCaptureMachine> capture_machine);
+  virtual ~ScreenCaptureDeviceCore();
+
+  // Asynchronous requests to change ScreenCaptureDeviceCore state.
+  void AllocateAndStart(const VideoCaptureParams& params,
+                        scoped_ptr<VideoCaptureDevice::Client> client);
+  void StopAndDeAllocate();
+
+ private:
+  // Flag indicating current state.
+  enum State {
+    kIdle,
+    kCapturing,
+    kError
+  };
+
+  void TransitionStateTo(State next_state);
+
+  // Called back in response to StartCaptureMachine().  |success| is true if
+  // capture machine succeeded to start.
+  void CaptureStarted(bool success);
+
+  // Stops capturing and notifies client_ of an error state.
+  void Error(const std::string& reason);
+
+  // Tracks that all activity occurs on the media stream manager's thread.
+  base::ThreadChecker thread_checker_;
+
+  // Current lifecycle state.
+  State state_;
+
+  // Tracks the CaptureMachine that's doing work on our behalf
+  // on the device thread or UI thread.
+  // This value should never be dereferenced by this class.
+  scoped_ptr<VideoCaptureMachine> capture_machine_;
+
+  // Our thread-safe capture oracle which serves as the gateway to the video
+  // capture pipeline. Besides the VideoCaptureDevice itself, it is the only
+  // component of the system with direct access to |client_|.
+  scoped_refptr<ThreadSafeCaptureOracle> oracle_proxy_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenCaptureDeviceCore);
+};
+
+
+}  // namespace media
+
+#endif  // MEDIA_CAPTURE_SCREEN_CAPTURE_DEVICE_CORE_H_