(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/rtc_base/constructor_magic.h b/rtc_base/constructor_magic.h
index 6b6e83c..e63c2ff 100644
--- a/rtc_base/constructor_magic.h
+++ b/rtc_base/constructor_magic.h
@@ -8,8 +8,8 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#ifndef RTC_BASE_CONSTRUCTORMAGIC_H_
-#define RTC_BASE_CONSTRUCTORMAGIC_H_
+#ifndef RTC_BASE_CONSTRUCTOR_MAGIC_H_
+#define RTC_BASE_CONSTRUCTOR_MAGIC_H_
 
 // Put this in the declarations for a class to be unassignable.
 #define RTC_DISALLOW_ASSIGN(TypeName) \
@@ -31,4 +31,4 @@
   TypeName() = delete;                               \
   RTC_DISALLOW_COPY_AND_ASSIGN(TypeName)
 
-#endif  // RTC_BASE_CONSTRUCTORMAGIC_H_
+#endif  // RTC_BASE_CONSTRUCTOR_MAGIC_H_