(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/sdk/android/native_api/video/video_source.cc b/sdk/android/native_api/video/video_source.cc
index aae1de7..a813f40 100644
--- a/sdk/android/native_api/video/video_source.cc
+++ b/sdk/android/native_api/video/video_source.cc
@@ -8,10 +8,10 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#include "sdk/android/native_api/video/videosource.h"
+#include "sdk/android/native_api/video/video_source.h"
 
-#include "sdk/android/src/jni/androidvideotracksource.h"
-#include "sdk/android/src/jni/nativecapturerobserver.h"
+#include "sdk/android/src/jni/android_video_track_source.h"
+#include "sdk/android/src/jni/native_capturer_observer.h"
 
 namespace webrtc {