(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/pc/peer_connection_wrapper.cc b/pc/peer_connection_wrapper.cc
index 05e7cf7..6bfb59f 100644
--- a/pc/peer_connection_wrapper.cc
+++ b/pc/peer_connection_wrapper.cc
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "pc/peerconnectionwrapper.h"
+#include "pc/peer_connection_wrapper.h"
 
 #include <stdint.h>
 #include <memory>
@@ -16,14 +16,14 @@
 #include <utility>
 #include <vector>
 
-#include "api/setremotedescriptionobserverinterface.h"
-#include "pc/sdputils.h"
-#include "pc/test/fakevideotracksource.h"
+#include "api/set_remote_description_observer_interface.h"
+#include "pc/sdp_utils.h"
+#include "pc/test/fake_video_track_source.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/function_view.h"
 #include "rtc_base/gunit.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/refcountedobject.h"
+#include "rtc_base/ref_counted_object.h"
 #include "test/gtest.h"
 
 namespace webrtc {