Revert of Add ability to scale to arbitrary factors

webrtc/media/base/adaptedvideotracksource.cc

Index: webrtc/media/base/adaptedvideotracksource.cc
diff --git a/webrtc/media/base/adaptedvideotracksource.cc b/webrtc/media/base/adaptedvideotracksource.cc
index 5900439e12103da6b32926b2e816fa076062b80e..acc147cc8903c6da2a7578fbcb8bb23a5c074659 100644
--- a/webrtc/media/base/adaptedvideotracksource.cc
+++ b/webrtc/media/base/adaptedvideotracksource.cc
@@ -13,11 +13,6 @@
 namespace rtc {
 
 AdaptedVideoTrackSource::AdaptedVideoTrackSource() {
-  thread_checker_.DetachFromThread();
-}
-
-AdaptedVideoTrackSource::AdaptedVideoTrackSource(int required_alignment)
-    : video_adapter_(required_alignment) {
   thread_checker_.DetachFromThread();
 }