Cleanup: Rename ARegion variables from ar to region

The old convention was easy to confuse with ScrArea.
Part of https://developer.blender.org/T74432.

This is mostly a batch rename with some manual fixing. Only single word
variable names are changed, no prefixed/suffixed names.

Brecht van Lommel and Campbell Barton both gave me a green light for
this convention change.

Also ran clan clang format on affected files.

1 files changed, 1 insertions, 1 deletions

diff --git a/source/blender/windowmanager/wm_event_system.h b/source/blender/windowmanager/wm_event_system.h
index 97c5980e3e7..ffa5baae9f1 100644
--- a/source/blender/windowmanager/wm_event_system.h
+++ b/source/blender/windowmanager/wm_event_system.h
@@ -45,7 +45,7 @@ enum eWM_EventHandlerType {
   WM_HANDLER_TYPE_KEYMAP,
 };
 
-typedef bool (*EventHandlerPoll)(const ARegion *ar, const wmEvent *event);
+typedef bool (*EventHandlerPoll)(const ARegion *region, const wmEvent *event);
 
 typedef struct wmEventHandler {
   struct wmEventHandler *next, *prev;