Image Capture v4l2: reset all user controls to default values when closing device fd

media/capture/video/linux/v4l2_capture_delegate.h

 // Copyright 2015 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_VIDEO_LINUX_V4L2_CAPTURE_DELEGATE_H_
 #define MEDIA_CAPTURE_VIDEO_LINUX_V4L2_CAPTURE_DELEGATE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 12 matching lines @@
 namespace tracked_objects {
 class Location;
 }  // namespace tracked_objects
 
 namespace media {
 
 // Class doing the actual Linux capture using V4L2 API. V4L2 SPLANE/MPLANE
 // capture specifics are implemented in derived classes. Created and destroyed
 // on the owner's thread, otherwise living and operating on |v4l2_task_runner_|.
 // TODO(mcasas): Make this class a non-ref-counted.
-class V4L2CaptureDelegate final
+class CAPTURE_EXPORT V4L2CaptureDelegate final
     : public base::RefCountedThreadSafe<V4L2CaptureDelegate> {
  public:
   // Retrieves the #planes for a given |fourcc|, or 0 if unknown.
   static size_t GetNumPlanesForFourCc(uint32_t fourcc);
   // Returns the Chrome pixel format for |v4l2_fourcc| or PIXEL_FORMAT_UNKNOWN.
   static VideoPixelFormat V4l2FourCcToChromiumPixelFormat(
       uint32_t v4l2_fourcc);
 
   // Composes a list of usable and supported pixel formats, in order of
   // preference, with MJPEG prioritised depending on |prefer_mjpeg|.
@@ skipping 14 matching lines @@
   void TakePhoto(VideoCaptureDevice::TakePhotoCallback callback);
 
   void GetPhotoCapabilities(
       VideoCaptureDevice::GetPhotoCapabilitiesCallback callback);
   void SetPhotoOptions(mojom::PhotoSettingsPtr settings,
                        VideoCaptureDevice::SetPhotoOptionsCallback callback);
 
   void SetRotation(int rotation);
 
  private:
+  friend class V4L2CaptureDelegateTest;
+
   friend class base::RefCountedThreadSafe<V4L2CaptureDelegate>;
   ~V4L2CaptureDelegate();
 
   class BufferTracker;
 
   // VIDIOC_QUERYBUFs a buffer from V4L2, creates a BufferTracker for it and
   // enqueues it (VIDIOC_QBUF) back into V4L2.
   bool MapAndQueueBuffer(int index);
 
   void DoCapture();
@@ skipping 23 matching lines @@
 
   // Clockwise rotation in degrees. This value should be 0, 90, 180, or 270.
   int rotation_;
 
   DISALLOW_COPY_AND_ASSIGN(V4L2CaptureDelegate);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_CAPTURE_VIDEO_LINUX_V4L2_CAPTURE_DELEGATE_H_