Remove RTC_DISALLOW_COPY_AND_ASSIGN from rtc_base/

Bug: webrtc:13555, webrtc:13082
Change-Id: I406b7f04497562866ea3329e97c5adc96e927b6f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/245680
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Artem Titov <titovartem@webrtc.org>
Commit-Queue: (Daniel.L) Byoungchan Lee <daniel.l@hpcnt.com>
Cr-Commit-Position: refs/heads/main@{#35691}
diff --git a/rtc_base/message_handler.h b/rtc_base/message_handler.h
index 62c8344..c5e05ca 100644
--- a/rtc_base/message_handler.h
+++ b/rtc_base/message_handler.h
@@ -14,7 +14,6 @@
 #include <utility>
 
 #include "api/function_view.h"
-#include "rtc_base/constructor_magic.h"
 #include "rtc_base/system/rtc_export.h"
 
 namespace rtc {
@@ -37,11 +36,12 @@
  public:
   ~MessageHandlerAutoCleanup() override;
 
+  MessageHandlerAutoCleanup(const MessageHandlerAutoCleanup&) = delete;
+  MessageHandlerAutoCleanup& operator=(const MessageHandlerAutoCleanup&) =
+      delete;
+
  protected:
   MessageHandlerAutoCleanup();
-
- private:
-  RTC_DISALLOW_COPY_AND_ASSIGN(MessageHandlerAutoCleanup);
 };
 
 }  // namespace rtc