[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/rtc_tools/video_file_writer_unittest.cc b/rtc_tools/video_file_writer_unittest.cc
index 11b1c37..4c4b1a5 100644
--- a/rtc_tools/video_file_writer_unittest.cc
+++ b/rtc_tools/video_file_writer_unittest.cc
@@ -8,9 +8,11 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <stdint.h>
+#include <cstdio>
 #include <string>
 
-#include "rtc_base/refcountedobject.h"
+#include "api/video/video_frame_buffer.h"
 #include "rtc_tools/video_file_reader.h"
 #include "rtc_tools/video_file_writer.h"
 #include "test/gtest.h"