temp: disable occlusion checker on macOS

shell/browser/feature_list.cc

@@ -19,6 +19,7 @@
 #include "third_party/blink/public/common/features.h"
 
 #if BUILDFLAG(IS_MAC)
+#include "content/common/features.h"  // nogncheck
 #include "device/base/features.h"  // nogncheck
 #endif
 
@@ -46,6 +47,12 @@ void InitializeFeatureList() {
       // 'custom dictionary word list API' spec to crash.
       std::string(",") + spellcheck::kWinDelaySpellcheckServiceInit.name;
 #endif
+
+#if BUILDFLAG(IS_MAC)
+  // Disable window occlusion checker.
+  disable_features +=
+      std::string(",") + features::kMacWebContentsOcclusion.name;
+#endif
   std::string platform_specific_enable_features =
       EnablePlatformSpecificFeatures();
   if (platform_specific_enable_features.size() > 0) {