Do not clear layer delegates when destroying the compositor.

This is the Mac version of
https://chromium-review.googlesource.com/c/chromium/src/+/1848911 .

Bug: 1016900
Change-Id: I59d2327d0c48f15b929247c0cce76aa35ee88678
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1877191
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Commit-Queue: ccameron <ccameron@chromium.org>
Reviewed-by: ccameron <ccameron@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710006}

ui/views/cocoa/native_widget_mac_ns_window_host.mm

@@ -553,8 +553,6 @@ void NativeWidgetMacNSWindowHost::DestroyCompositor() {
     // NativeWidgetNSWindowBridge.
     DCHECK_EQ(this, layer()->owner());
     layer()->CompleteAllAnimations();
-    layer()->SuppressPaint();
-    layer()->set_delegate(nullptr);
   }
   DestroyLayer();
   if (!compositor_)