(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/rtc_stats_integrationtest.cc b/pc/rtc_stats_integrationtest.cc
index aa45975..cae01ae 100644
--- a/pc/rtc_stats_integrationtest.cc
+++ b/pc/rtc_stats_integrationtest.cc
@@ -22,25 +22,25 @@
 #include "api/audio_codecs/builtin_audio_decoder_factory.h"
 #include "api/audio_codecs/builtin_audio_encoder_factory.h"
 #include "api/audio_options.h"
-#include "api/datachannelinterface.h"
-#include "api/peerconnectioninterface.h"
-#include "api/rtpreceiverinterface.h"
-#include "api/rtpsenderinterface.h"
-#include "api/stats/rtcstats.h"
+#include "api/data_channel_interface.h"
+#include "api/peer_connection_interface.h"
+#include "api/rtp_receiver_interface.h"
+#include "api/rtp_sender_interface.h"
+#include "api/stats/rtc_stats.h"
+#include "api/stats/rtc_stats_report.h"
 #include "api/stats/rtcstats_objects.h"
-#include "api/stats/rtcstatsreport.h"
-#include "api/test/fakeconstraints.h"
-#include "pc/rtcstatstraversal.h"
-#include "pc/test/peerconnectiontestwrapper.h"
-#include "pc/test/rtcstatsobtainer.h"
+#include "api/test/fake_constraints.h"
+#include "pc/rtc_stats_traversal.h"
+#include "pc/test/peer_connection_test_wrapper.h"
+#include "pc/test/rtc_stats_obtainer.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/event_tracer.h"
 #include "rtc_base/gunit.h"
-#include "rtc_base/refcountedobject.h"
+#include "rtc_base/ref_counted_object.h"
 #include "rtc_base/scoped_ref_ptr.h"
 #include "rtc_base/thread.h"
 #include "rtc_base/trace_event.h"
-#include "rtc_base/virtualsocketserver.h"
+#include "rtc_base/virtual_socket_server.h"
 #include "test/gtest.h"
 
 namespace webrtc {