Revert "Add file capturer to AppRTCMobile on simulator."

This reverts commit 5adcd198752b651f7b7e9199a91f9b873b7d7237.

Reason for revert: <INSERT REASONING HERE>

Original change's description:
> Add file capturer to AppRTCMobile on simulator.
> 
> To achieve this, the CL does the following
> - Adds sample mp4 video
> - Refactors the existing RTCFileVideoCapturer to achieve continious
> capture and adds tests.
> 
> Bug: webrtc:8406
> Change-Id: Ibc0891176c58ec9053b42e340d2113036e7199ec
> Reviewed-on: https://webrtc-review.googlesource.com/12180
> Reviewed-by: Anders Carlsson <andersc@webrtc.org>
> Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
> Commit-Queue: Daniela Jovanoska Petrenko <denicija@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#20598}

TBR=magjed@webrtc.org,andersc@webrtc.org,denicija@webrtc.org

Change-Id: I73b35c67296c964f65d206454ac1329b4b979628
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:8406
Reviewed-on: https://webrtc-review.googlesource.com/21240
Reviewed-by: Daniela Jovanoska Petrenko <denicija@webrtc.org>
Commit-Queue: Daniela Jovanoska Petrenko <denicija@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20599}

sdk/objc/Framework/Classes/PeerConnection/RTCFileVideoCapturer.h

@@ -0,0 +1,26 @@
+/*
+ *  Copyright 2017 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 <Foundation/Foundation.h>
+#import <WebRTC/RTCVideoCapturer.h>
+
+/**
+ * RTCVideoCapturer that reads buffers from file.
+ *
+ * Per design, the file capturer can only be run once and once stopped it cannot run again.
+ * To run another file capture session, create new instance of the class.
+ */
+NS_CLASS_AVAILABLE_IOS(10)
+@interface RTCFileVideoCapturer : RTCVideoCapturer
+
+- (void)startCapturingFromFileNamed:(NSString *)nameOfFile;
+- (void)stopCapture;
+
+@end