Remove maximum frametime to allow the camera to adjust based on the lighting conditions.

webrtc/sdk/objc/Framework/Classes/PeerConnection/RTCCameraVideoCapturer.m

 /*
  *  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.
  */
 
@@ skipping 390 matching lines @@
 }
 
 #pragma mark - Private, called inside capture queue
 
 - (void)updateDeviceCaptureFormat:(AVCaptureDeviceFormat *)format fps:(NSInteger)fps {
   NSAssert([RTCDispatcher isOnQueueForType:RTCDispatcherTypeCaptureSession],
            @"updateDeviceCaptureFormat must be called on the capture queue.");
   @try {
     _currentDevice.activeFormat = format;
     _currentDevice.activeVideoMinFrameDuration = CMTimeMake(1, fps);
-    _currentDevice.activeVideoMaxFrameDuration = CMTimeMake(1, fps);
   } @catch (NSException *exception) {
     RTCLogError(@"Failed to set active format!\n User info:%@", exception.userInfo);
     return;
   }
 }
 
 - (void)reconfigureCaptureSessionInput {
   NSAssert([RTCDispatcher isOnQueueForType:RTCDispatcherTypeCaptureSession],
            @"reconfigureCaptureSessionInput must be called on the capture queue.");
   NSError *error = nil;
@@ skipping 17 matching lines @@
 
 - (void)updateOrientation {
   NSAssert([RTCDispatcher isOnQueueForType:RTCDispatcherTypeCaptureSession],
            @"updateOrientation must be called on the capture queue.");
 #if TARGET_OS_IPHONE
   _orientation = [UIDevice currentDevice].orientation;
 #endif
 }
 
 @end