Revert "Simple Default ObjC video codec factories."

This reverts commit 30915a742d86df55ac5c04501c0e8104675a612e.

Reason for revert: Breaks downstream.

Original change's description:
> Simple Default ObjC video codec factories.
> 
> Move the simple video encoder/decoder factory from AppRTCMobile into the
> public API so users who don't have special requirements for video codecs
> can easily get started.
> 
> Also clean up the API a little.
> 
> This CL replaces the more flexible default factories in
> https://webrtc-review.googlesource.com/c/src/+/7741 and clients that
> want to implement their own codecs will have to supply their own
> encoder/decoder factories as well. The benefits of the approach in
> this CL are a simpler API and less effects on the rest of the code.
> 
> Bug: None
> Change-Id: I4ed94090d778b4fc38b49864de1d4de4ff125d6a
> Reviewed-on: https://webrtc-review.googlesource.com/15141
> Reviewed-by: Kári Helgason <kthelgason@webrtc.org>
> Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
> Commit-Queue: Anders Carlsson <andersc@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#20441}

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

Change-Id: I3d4395cc9667e6c6cdb33a3b0f5c5fb5bfde9028
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: None
Reviewed-on: https://webrtc-review.googlesource.com/15182
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Commit-Queue: Oskar Sundbom <ossu@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20446}

sdk/objc/Framework/Classes/PeerConnection/RTCDefaultVideoEncoderFactory.m

@@ -1,74 +0,0 @@
-/*
- *  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 "WebRTC/RTCVideoCodecFactory.h"
-
-#import "WebRTC/RTCVideoCodec.h"
-#import "WebRTC/RTCVideoCodecH264.h"
-#import "WebRTC/RTCVideoEncoderVP8.h"
-#import "WebRTC/RTCVideoEncoderVP9.h"
-
-@implementation RTCDefaultVideoEncoderFactory
-
-@synthesize preferredCodec;
-
-+ (NSArray<RTCVideoCodecInfo *> *)supportedCodecs {
-  NSDictionary<NSString *, NSString *> *constrainedHighParams = @{
-    @"profile-level-id" : kRTCLevel31ConstrainedHigh,
-    @"level-asymmetry-allowed" : @"1",
-    @"packetization-mode" : @"1",
-  };
-  RTCVideoCodecInfo *constrainedHighInfo =
-      [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecH264Name
-                                   parameters:constrainedHighParams];
-
-  NSDictionary<NSString *, NSString *> *constrainedBaselineParams = @{
-    @"profile-level-id" : kRTCLevel31ConstrainedBaseline,
-    @"level-asymmetry-allowed" : @"1",
-    @"packetization-mode" : @"1",
-  };
-  RTCVideoCodecInfo *constrainedBaselineInfo =
-      [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecH264Name
-                                   parameters:constrainedBaselineParams];
-
-  RTCVideoCodecInfo *vp8Info = [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecVp8Name];
-
-  RTCVideoCodecInfo *vp9Info = [[RTCVideoCodecInfo alloc] initWithName:kRTCVideoCodecVp9Name];
-
-  return @[ constrainedHighInfo, constrainedBaselineInfo, vp8Info, vp9Info ];
-}
-
-- (id<RTCVideoEncoder>)createEncoder:(RTCVideoCodecInfo *)info {
-  if ([info.name isEqualToString:kRTCVideoCodecH264Name]) {
-    return [[RTCVideoEncoderH264 alloc] initWithCodecInfo:info];
-  } else if ([info.name isEqualToString:kRTCVideoCodecVp8Name]) {
-    return [RTCVideoEncoderVP8 vp8Encoder];
-  } else if ([info.name isEqualToString:kRTCVideoCodecVp9Name]) {
-    return [RTCVideoEncoderVP9 vp9Encoder];
-  }
-
-  return nil;
-}
-
-- (NSArray<RTCVideoCodecInfo *> *)supportedCodecs {
-  NSMutableArray<RTCVideoCodecInfo *> *codecs = [[[self class] supportedCodecs] mutableCopy];
-
-  NSMutableArray<RTCVideoCodecInfo *> *orderedCodecs = [NSMutableArray array];
-  NSUInteger index = [codecs indexOfObject:self.preferredCodec];
-  if (index != NSNotFound) {
-    [orderedCodecs addObject:[codecs objectAtIndex:index]];
-    [codecs removeObjectAtIndex:index];
-  }
-  [orderedCodecs addObjectsFromArray:codecs];
-
-  return [orderedCodecs copy];
-}
-
-@end