[heap] Do not start array buffer sweeping task without any work

RequestSweep started an array buffer sweeping task even when there was
no work.

Bug: chromium:1045937
Change-Id: Ieb0835284f898dbc9b899d2b4118d9f7f6108a6f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2020961
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66004}

src/heap/array-buffer-sweeper.cc

@@ -100,6 +100,9 @@ void ArrayBufferSweeper::RequestSweepFull() {
 void ArrayBufferSweeper::RequestSweep(SweepingScope scope) {
   DCHECK(!sweeping_in_progress_);
 
+  if (young_.IsEmpty() && (old_.IsEmpty() || scope == SweepingScope::Young))
+    return;
+
   if (!heap_->IsTearingDown() && !heap_->ShouldReduceMemory() &&
       FLAG_concurrent_array_buffer_sweeping) {
     Prepare(scope);