browser(webkit): restore occlusion detection disabled

browser_patches/webkit/BUILD_NUMBER

@@ -1,2 +1,2 @@
-1455
-Changed: yurys@chromium.org Tue 30 Mar 2021 02:36:32 PM PDT
+1456
+Changed: pavel.feldman@gmail.com Tue Mar 30 23:50:14 PDT 2021

browser_patches/webkit/embedder/Playwright/mac/BrowserWindowController.m

@@ -163,6 +163,7 @@ static void* keyValueObservingContext = &keyValueObservingContext;
 - (void)awakeFromNib
 {
     _webView = [[WKWebView alloc] initWithFrame:[containerView bounds] configuration:_configuration];
+    _webView._windowOcclusionDetectionEnabled = NO;
 
     _webView.allowsMagnification = YES;
     _webView.allowsBackForwardNavigationGestures = YES;