[Cleanup] Add missing #include. Remove useless ones. IWYU part 2.

This is a follow-up to
https://webrtc-review.googlesource.com/c/src/+/106280.
This time the whole code base is covered.
Some files may have not been fixed though, whenever the IWYU tool
was breaking the build.

Bug: webrtc:8311
Change-Id: I2c31f552a87e887d33931d46e87b6208b1e483ef
Reviewed-on: https://webrtc-review.googlesource.com/c/111965
Commit-Queue: Yves Gerey <yvesg@google.com>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25830}
diff --git a/video/stream_synchronization.h b/video/stream_synchronization.h
index 78fcf72..9050d22 100644
--- a/video/stream_synchronization.h
+++ b/video/stream_synchronization.h
@@ -11,7 +11,7 @@
 #ifndef VIDEO_STREAM_SYNCHRONIZATION_H_
 #define VIDEO_STREAM_SYNCHRONIZATION_H_
 
-#include <list>
+#include <stdint.h>
 
 #include "system_wrappers/include/rtp_to_ntp_estimator.h"