Rotate frames correctly for back camera

media/capture/video/linux/video_capture_device_linux.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.
 
 // Linux specific implementation of VideoCaptureDevice.
 // V4L2 is used for capturing. V4L2 does not provide its own thread for
 // capturing so this implementation uses a Chromium thread for fetching frames
 // from V4L2.
 
 #ifndef MEDIA_CAPTURE_VIDEO_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_
 #define MEDIA_CAPTURE_VIDEO_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/files/file_util.h"
 #include "base/files/scoped_file.h"
+#include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/threading/thread.h"
+#include "media/capture/video/linux/camera_characteristics.h"
 #include "media/capture/video/video_capture_device.h"
 #include "media/capture/video_capture_types.h"
 
 namespace media {
 
 class V4L2CaptureDelegate;
 
 // Linux V4L2 implementation of VideoCaptureDevice.
 class VideoCaptureDeviceLinux : public VideoCaptureDevice {
  public:
@@ skipping 21 matching lines @@
 
   // Internal delegate doing the actual capture setting, buffer allocation and
   // circulation with the V4L2 API. Created and deleted in the thread where
   // VideoCaptureDeviceLinux lives but otherwise operating on |v4l2_thread_|.
   scoped_refptr<V4L2CaptureDelegate> capture_impl_;
 
   base::Thread v4l2_thread_;  // Thread used for reading data from the device.
 
   const VideoCaptureDeviceDescriptor device_descriptor_;
 
+  base::LazyInstance<CameraCharacteristics> camera_characteristics_;
+
+  // True if the camera is world-facing. False if the camera is user-facing,
+  // external, or unknown.
+  bool is_back_camera_;
+
   DISALLOW_IMPLICIT_CONSTRUCTORS(VideoCaptureDeviceLinux);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_LINUX_VIDEO_CAPTURE_DEVICE_LINUX_H_