(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/sctp/sctp_transport_unittest.cc b/media/sctp/sctp_transport_unittest.cc
index c63bde8..0170785 100644
--- a/media/sctp/sctp_transport_unittest.cc
+++ b/media/sctp/sctp_transport_unittest.cc
@@ -15,12 +15,12 @@
 #include <string>
 #include <vector>
 
-#include "media/sctp/sctptransport.h"
-#include "p2p/base/fakedtlstransport.h"
-#include "rtc_base/copyonwritebuffer.h"
+#include "media/sctp/sctp_transport.h"
+#include "p2p/base/fake_dtls_transport.h"
+#include "rtc_base/copy_on_write_buffer.h"
 #include "rtc_base/gunit.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/messagequeue.h"
+#include "rtc_base/message_queue.h"
 #include "rtc_base/thread.h"
 #include "test/gtest.h"