ObjC SDK: Stop using built-in SW video codecs

This CL removes the use of default built-in SW in the ObjC layer. If a
client want to depend on the video SW codecs, they must inject them
explicitly.

Bug: webrtc:7925
Change-Id: If752e7f02109ff768dc5ec38d935203de85987c2
Reviewed-on: https://webrtc-review.googlesource.com/69800
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Anders Carlsson <andersc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23073}
diff --git a/sdk/objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm b/sdk/objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm
index 3289f01..ffdbd9d 100644
--- a/sdk/objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm
+++ b/sdk/objc/Framework/Classes/VideoToolbox/RTCVideoEncoderH264.mm
@@ -167,8 +167,8 @@
                                 rotation:encodeParams->rotation];
 }
 
-// Extract VideoToolbox profile out of the cricket::VideoCodec. If there is no
-// specific VideoToolbox profile for the specified level, AutoLevel will be
+// Extract VideoToolbox profile out of the webrtc::SdpVideoFormat. If there is
+// no specific VideoToolbox profile for the specified level, AutoLevel will be
 // returned. The user must initialize the encoder with a resolution and
 // framerate conforming to the selected H264 level regardless.
 CFStringRef ExtractProfile(webrtc::SdpVideoFormat videoFormat) {