Delete macro RTC_ACCESS_ON, replaced by RTC_GUARDED_BY.

Both macros do the same thing, as wrappers for
__attribute__((guarded_by)), and more names for the same thing doesn't
add to clarity.

Bug: none
Change-Id: Iaaf7b21dbf3345ee90fee22c39b636823d195eb0
Reviewed-on: https://webrtc-review.googlesource.com/48361
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21929}
diff --git a/rtc_base/thread_checker.h b/rtc_base/thread_checker.h
index 028e9bf..cc03b8d 100644
--- a/rtc_base/thread_checker.h
+++ b/rtc_base/thread_checker.h
@@ -101,7 +101,7 @@
 }  // namespace internal
 }  // namespace rtc
 
-// RTC_RUN_ON/RTC_ACCESS_ON/RTC_DCHECK_RUN_ON macros allows to annotate
+// RTC_RUN_ON/RTC_GUARDED_BY/RTC_DCHECK_RUN_ON macros allows to annotate
 // variables are accessed from same thread/task queue.
 // Using tools designed to check mutexes, it checks at compile time everywhere
 // variable is access, there is a run-time dcheck thread/task queue is correct.
@@ -115,7 +115,7 @@
 //
 //  private:
 //   rtc::Thread* network_thread_;
-//   int transport_ RTC_ACCESS_ON(network_thread_);
+//   int transport_ RTC_GUARDED_BY(network_thread_);
 // };
 //
 // class ExampleThreadChecker {
@@ -131,7 +131,7 @@
 //   }
 //
 //  private:
-//   int pacer_var_ RTC_ACCESS_ON(pacer_thread_checker_);
+//   int pacer_var_ RTC_GUARDED_BY(pacer_thread_checker_);
 //   rtc::ThreadChecker pacer_thread_checker_;
 // };
 //
@@ -147,7 +147,7 @@
 //
 //    private:
 //     rtc::TaskQueue* const encoder_queue_;
-//     Frame var_ RTC_ACCESS_ON(encoder_queue_);
+//     Frame var_ RTC_GUARDED_BY(encoder_queue_);
 //   };
 //
 //   void Encode() {
@@ -162,10 +162,6 @@
 //   rtc::scoped_ref_ptr<Encoder> encoder_;
 // }
 
-// Document if a variable/field is not shared and should be accessed from
-// same thread/task queue.
-#define RTC_ACCESS_ON(x) RTC_THREAD_ANNOTATION_ATTRIBUTE__(guarded_by(x))
-
 // Document if a function expected to be called from same thread/task queue.
 #define RTC_RUN_ON(x) RTC_THREAD_ANNOTATION_ATTRIBUTE__(exclusive_locks_required(x))