(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/api/audio_codecs/audio_decoder.h b/api/audio_codecs/audio_decoder.h
index 684266a..e4e5e1e 100644
--- a/api/audio_codecs/audio_decoder.h
+++ b/api/audio_codecs/audio_decoder.h
@@ -19,7 +19,7 @@
 #include "absl/types/optional.h"
 #include "api/array_view.h"
 #include "rtc_base/buffer.h"
-#include "rtc_base/constructormagic.h"
+#include "rtc_base/constructor_magic.h"
 
 namespace webrtc {
 
diff --git a/api/audio_codecs/audio_decoder_factory.h b/api/audio_codecs/audio_decoder_factory.h
index 3d80958..c36a0e1 100644
--- a/api/audio_codecs/audio_decoder_factory.h
+++ b/api/audio_codecs/audio_decoder_factory.h
@@ -18,7 +18,7 @@
 #include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_decoder.h"
 #include "api/audio_codecs/audio_format.h"
-#include "rtc_base/refcount.h"
+#include "rtc_base/ref_count.h"
 
 namespace webrtc {
 
diff --git a/api/audio_codecs/audio_decoder_factory_template.h b/api/audio_codecs/audio_decoder_factory_template.h
index 22bb7de..e7f1443 100644
--- a/api/audio_codecs/audio_decoder_factory_template.h
+++ b/api/audio_codecs/audio_decoder_factory_template.h
@@ -15,7 +15,7 @@
 #include <vector>
 
 #include "api/audio_codecs/audio_decoder_factory.h"
-#include "rtc_base/refcountedobject.h"
+#include "rtc_base/ref_counted_object.h"
 #include "rtc_base/scoped_ref_ptr.h"
 
 namespace webrtc {
diff --git a/api/audio_codecs/audio_encoder_factory.h b/api/audio_codecs/audio_encoder_factory.h
index a5fd561..48995a8 100644
--- a/api/audio_codecs/audio_encoder_factory.h
+++ b/api/audio_codecs/audio_encoder_factory.h
@@ -18,7 +18,7 @@
 #include "api/audio_codecs/audio_codec_pair_id.h"
 #include "api/audio_codecs/audio_encoder.h"
 #include "api/audio_codecs/audio_format.h"
-#include "rtc_base/refcount.h"
+#include "rtc_base/ref_count.h"
 
 namespace webrtc {
 
diff --git a/api/audio_codecs/audio_encoder_factory_template.h b/api/audio_codecs/audio_encoder_factory_template.h
index 2088619..01a6a74 100644
--- a/api/audio_codecs/audio_encoder_factory_template.h
+++ b/api/audio_codecs/audio_encoder_factory_template.h
@@ -15,7 +15,7 @@
 #include <vector>
 
 #include "api/audio_codecs/audio_encoder_factory.h"
-#include "rtc_base/refcountedobject.h"
+#include "rtc_base/ref_counted_object.h"
 #include "rtc_base/scoped_ref_ptr.h"
 
 namespace webrtc {