Fix for RtcEventLog ObjC interface

This moves the RtcEventLog start/stop functions to PeerConnection on the objC interface.

BUG=
R=tkchin@webrtc.org

Review URL: https://codereview.webrtc.org/2106103003 .

Cr-Commit-Position: refs/heads/master@{#13337}

webrtc/sdk/objc/Framework/Classes/RTCPeerConnectionFactory.mm

@@ -10,8 +10,6 @@
 
 #import "RTCPeerConnectionFactory+Private.h"
 
-#include <memory>
-
 #import "NSString+StdString.h"
 #import "RTCAVFoundationVideoSource+Private.h"
 #import "RTCAudioTrack+Private.h"
@@ -19,15 +17,11 @@
 #import "RTCPeerConnection+Private.h"
 #import "RTCVideoSource+Private.h"
 #import "RTCVideoTrack+Private.h"
-#import "WebRTC/RTCLogging.h"
-
-#include "webrtc/base/checks.h"
 
 @implementation RTCPeerConnectionFactory {
   std::unique_ptr<rtc::Thread> _networkThread;
   std::unique_ptr<rtc::Thread> _workerThread;
   std::unique_ptr<rtc::Thread> _signalingThread;
-  BOOL _hasStartedRtcEventLog;
 }
 
 @synthesize nativeFactory = _nativeFactory;
@@ -54,29 +48,6 @@
   return self;
 }
 
-- (BOOL)startRtcEventLogWithFilePath:(NSString *)filePath
-                      maxSizeInBytes:(int64_t)maxSizeInBytes {
-  RTC_DCHECK(filePath.length);
-  RTC_DCHECK_GT(maxSizeInBytes, 0);
-  RTC_DCHECK(!_hasStartedRtcEventLog);
-  if (_hasStartedRtcEventLog) {
-    RTCLogError(@"Event logging already started.");
-    return NO;
-  }
-  int fd = open(filePath.UTF8String, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
-  if (fd < 0) {
-    RTCLogError(@"Error opening file: %@. Error: %d", filePath, errno);
-    return NO;
-  }
-  _hasStartedRtcEventLog = _nativeFactory->StartRtcEventLog(fd, maxSizeInBytes);
-  return _hasStartedRtcEventLog;
-}
-
-- (void)stopRtcEventLog {
-  _nativeFactory->StopRtcEventLog();
-  _hasStartedRtcEventLog = NO;
-}
-
 - (RTCAVFoundationVideoSource *)avFoundationVideoSourceWithConstraints:
     (nullable RTCMediaConstraints *)constraints {
   return [[RTCAVFoundationVideoSource alloc] initWithFactory:self