Split avfoundationcapturer classes in separate files.

webrtc/sdk/objc/Framework/Classes/avfoundationformatmapper.h

+/*
+ *  Copyright 2016 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#import <AVFoundation/AVFoundation.h>
+#import <Foundation/Foundation.h>
+
+#include "webrtc/media/base/videocapturer.h"
+
+namespace webrtc {
+// Mapping from AVCaptureDeviceFormat to cricket::VideoFormat for given input
+// device.
+extern std::set<cricket::VideoFormat> GetSupportedVideoFormatsForDevice(
+    AVCaptureDevice* device);
+
+// Sets device format for the provided capture device. Returns YES/NO depending
+// on success.
+extern bool SetFormatForCaptureDevice(AVCaptureDevice* device,
+                                      AVCaptureSession* session,
+                                      const cricket::VideoFormat& format);
+}