[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}

modules/video_coding/codecs/multiplex/augmented_video_frame_buffer.cc

@@ -9,6 +9,10 @@
  */
 
 #include "modules/video_coding/codecs/multiplex/include/augmented_video_frame_buffer.h"
+
+#include <stdint.h>
+#include <utility>
+
 #include "api/video/video_frame_buffer.h"
 
 namespace webrtc {

modules/video_coding/codecs/multiplex/include/augmented_video_frame_buffer.h

@@ -11,9 +11,11 @@
 #ifndef MODULES_VIDEO_CODING_CODECS_MULTIPLEX_INCLUDE_AUGMENTED_VIDEO_FRAME_BUFFER_H_
 #define MODULES_VIDEO_CODING_CODECS_MULTIPLEX_INCLUDE_AUGMENTED_VIDEO_FRAME_BUFFER_H_
 
+#include <cstdint>
 #include <memory>
 
 #include "api/video/video_frame_buffer.h"
+#include "rtc_base/scoped_ref_ptr.h"
 
 namespace webrtc {
 class AugmentedVideoFrameBuffer : public VideoFrameBuffer {

modules/video_coding/codecs/multiplex/multiplex_encoded_image_packer.cc

@@ -14,6 +14,7 @@
 #include <utility>
 
 #include "modules/rtp_rtcp/source/byte_io.h"
+#include "rtc_base/checks.h"
 
 namespace webrtc {
 int PackHeader(uint8_t* buffer, MultiplexImageHeader header) {

modules/video_coding/codecs/multiplex/multiplex_encoded_image_packer.h

@@ -11,6 +11,7 @@
 #ifndef MODULES_VIDEO_CODING_CODECS_MULTIPLEX_MULTIPLEX_ENCODED_IMAGE_PACKER_H_
 #define MODULES_VIDEO_CODING_CODECS_MULTIPLEX_MULTIPLEX_ENCODED_IMAGE_PACKER_H_
 
+#include <cstdint>
 #include <memory>
 #include <vector>
 

modules/video_coding/codecs/multiplex/test/multiplex_adapter_unittest.cc

@@ -8,10 +8,25 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <stddef.h>
+#include <cstdint>
+#include <memory>
+#include <utility>
+#include <vector>
+
 #include "absl/memory/memory.h"
+#include "absl/types/optional.h"
 #include "api/test/mock_video_decoder_factory.h"
 #include "api/test/mock_video_encoder_factory.h"
+#include "api/video/encoded_image.h"
+#include "api/video/video_frame.h"
+#include "api/video/video_frame_buffer.h"
+#include "api/video/video_rotation.h"
 #include "api/video_codecs/sdp_video_format.h"
+#include "api/video_codecs/video_codec.h"
+#include "api/video_codecs/video_decoder.h"
+#include "api/video_codecs/video_encoder.h"
+#include "common_types.h"  // NOLINT(build/include)
 #include "common_video/include/video_frame_buffer.h"
 #include "common_video/libyuv/include/webrtc_libyuv.h"
 #include "media/base/mediaconstants.h"
@@ -21,7 +36,13 @@
 #include "modules/video_coding/codecs/multiplex/multiplex_encoded_image_packer.h"
 #include "modules/video_coding/codecs/test/video_codec_unittest.h"
 #include "modules/video_coding/codecs/vp9/include/vp9.h"
+#include "modules/video_coding/include/video_codec_interface.h"
+#include "modules/video_coding/include/video_error_codes.h"
 #include "rtc_base/keep_ref_until_done.h"
+#include "rtc_base/refcountedobject.h"
+#include "rtc_base/scoped_ref_ptr.h"
+#include "test/gmock.h"
+#include "test/gtest.h"
 #include "test/video_codec_settings.h"
 
 using testing::_;