(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/jsep_ice_candidate.h b/api/jsep_ice_candidate.h
index 9cc7443..5b22454 100644
--- a/api/jsep_ice_candidate.h
+++ b/api/jsep_ice_candidate.h
@@ -11,8 +11,8 @@
 // TODO(deadbeef): Move this out of api/; it's an implementation detail and
 // shouldn't be used externally.
 
-#ifndef API_JSEPICECANDIDATE_H_
-#define API_JSEPICECANDIDATE_H_
+#ifndef API_JSEP_ICE_CANDIDATE_H_
+#define API_JSEP_ICE_CANDIDATE_H_
 
 #include <stddef.h>
 #include <string>
@@ -20,7 +20,7 @@
 
 #include "api/candidate.h"
 #include "api/jsep.h"
-#include "rtc_base/constructormagic.h"
+#include "rtc_base/constructor_magic.h"
 
 namespace webrtc {
 
@@ -82,4 +82,4 @@
 
 }  // namespace webrtc
 
-#endif  // API_JSEPICECANDIDATE_H_
+#endif  // API_JSEP_ICE_CANDIDATE_H_