Split iOS sdk in to separate targets

This CL splits the iOS sdk into separate static libraries for video,
audio, ui, common, and peerconnection-related code. This will in the
future make it easier to compile WebRTC without unneeded components.

BUG=webrtc:4867

Review-Url: https://codereview.webrtc.org/2862543002
Cr-Commit-Position: refs/heads/master@{#18166}

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

@@ -1,29 +0,0 @@
-/*
- *  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.
- */
-
-#include <set>
-
-#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.
-std::set<cricket::VideoFormat> GetSupportedVideoFormatsForDevice(
-    AVCaptureDevice* device);
-
-// Sets device format for the provided capture device. Returns YES/NO depending
-// on success.
-bool SetFormatForCaptureDevice(AVCaptureDevice* device,
-                               AVCaptureSession* session,
-                               const cricket::VideoFormat& format);
-}