(4) Rename files to snake_case: update BUILD.gn, include paths, header guards, and DEPS entries

Mechanically generated by running this command:

tools_webrtc/do-renames.sh update all-renames.txt && git cl format

Then manually updating:

tools_webrtc/sanitizers/tsan_suppressions_webrtc.cc

Bug: webrtc:10159
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Change-Id: I54824cd91dada8fc3ee3d098f971bc319d477833
Reviewed-on: https://webrtc-review.googlesource.com/c/115653
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26226}
diff --git a/sdk/objc/components/video_codec/RTCH264ProfileLevelId.mm b/sdk/objc/components/video_codec/RTCH264ProfileLevelId.mm
index 359656c..afd9fcb 100644
--- a/sdk/objc/components/video_codec/RTCH264ProfileLevelId.mm
+++ b/sdk/objc/components/video_codec/RTCH264ProfileLevelId.mm
@@ -17,7 +17,7 @@
 #endif
 
 #include "media/base/h264_profile_level_id.h"
-#include "media/base/mediaconstants.h"
+#include "media/base/media_constants.h"
 
 namespace {
 
diff --git a/sdk/objc/components/video_codec/RTCVideoDecoderH264.mm b/sdk/objc/components/video_codec/RTCVideoDecoderH264.mm
index 3bfb918..69ccc90 100644
--- a/sdk/objc/components/video_codec/RTCVideoDecoderH264.mm
+++ b/sdk/objc/components/video_codec/RTCVideoDecoderH264.mm
@@ -26,7 +26,7 @@
 #include "modules/video_coding/include/video_error_codes.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/timeutils.h"
+#include "rtc_base/time_utils.h"
 #include "sdk/objc/components/video_codec/nalu_rewriter.h"
 
 // Struct that we pass to the decoder per frame to decode. We receive it again
diff --git a/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm b/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm
index f6690b6..51fa51e 100644
--- a/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm
+++ b/sdk/objc/components/video_codec/RTCVideoEncoderH264.mm
@@ -36,7 +36,7 @@
 #include "modules/video_coding/include/video_error_codes.h"
 #include "rtc_base/buffer.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/timeutils.h"
+#include "rtc_base/time_utils.h"
 #include "sdk/objc/components/video_codec/nalu_rewriter.h"
 #include "third_party/libyuv/include/libyuv/convert_from.h"