(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/media/base/video_adapter_unittest.cc b/media/base/video_adapter_unittest.cc
index d7b328f..f50e13b 100644
--- a/media/base/video_adapter_unittest.cc
+++ b/media/base/video_adapter_unittest.cc
@@ -14,9 +14,9 @@
 
 #include "absl/memory/memory.h"
 #include "api/video/video_frame.h"
-#include "media/base/fakeframesource.h"
-#include "media/base/videoadapter.h"
-#include "rtc_base/timeutils.h"
+#include "media/base/fake_frame_source.h"
+#include "media/base/video_adapter.h"
+#include "rtc_base/time_utils.h"
 #include "test/gtest.h"
 
 namespace cricket {