In ScreenCapturerSck don't restart on SelectSource if display didn't change

Bug: webrtc:367915807
Change-Id: I637b7f46a766fe9120f3f30c15f3903f5aec1d3d
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/365087
Reviewed-by: Alexander Cooper <alcooper@chromium.org>
Commit-Queue: Andreas Pehrson <apehrson@mozilla.com>
Cr-Commit-Position: refs/heads/main@{#44210}
diff --git a/modules/desktop_capture/mac/screen_capturer_sck.mm b/modules/desktop_capture/mac/screen_capturer_sck.mm
index 9379940..479b5ba 100644
--- a/modules/desktop_capture/mac/screen_capturer_sck.mm
+++ b/modules/desktop_capture/mac/screen_capturer_sck.mm
@@ -203,6 +203,9 @@
   bool stream_started = false;
   {
     MutexLock lock(&lock_);
+    if (current_display_ == id) {
+      return true;
+    }
     current_display_ = id;
 
     if (stream_) {