Move V4L2 code into a webcam helper class.

extensions/browser/api/webcam_private/v4l2_webcam.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 EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_V4L2_WEBCAM_H_
+#define EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_V4L2_WEBCAM_H_
+
+#include "extensions/browser/api/webcam_private/webcam.h"
+
+#include "base/files/scoped_file.h"
+
+namespace extensions {
+
+class V4L2Webcam : public Webcam {
+ public:
+  V4L2Webcam(const std::string& device_id);
+  ~V4L2Webcam() override;
+
+  bool Open();
+
+ private:
+  bool EnsureLogitechCommandsMapped();
+  bool SetWebcamParameter(int fd, uint32_t control_id, int value);
+  bool GetWebcamParameter(int fd, uint32_t control_id, int* value);
+
+  // Webcam:
+  void Reset(bool pan, bool tilt, bool zoom) override;
+  bool GetPan(int* value) override;
+  bool GetTilt(int* value) override;
+  bool GetZoom(int* value) override;
+  bool SetPan(int value) override;
+  bool SetTilt(int value) override;
+  bool SetZoom(int value) override;
+  bool SetPanDirection(PanDirection direction) override;
+  bool SetTiltDirection(TiltDirection direction) override;
+
+  const std::string device_id_;
+  base::ScopedFD fd_;
+
+  DISALLOW_COPY_AND_ASSIGN(V4L2Webcam);
+};
+
+
+}  // namespace extensions
+
+#endif  // EXTENSIONS_BROWSER_API_WEBCAM_PRIVATE_V4L2_WEBCAM_H_