[heap] Avoid fast promotion print when the gc ignore scavenger is on.

Change-Id: Ia1b4aa36b828b5bd6273fc15381c666d23c5746b
Reviewed-on: https://chromium-review.googlesource.com/1085462Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Rodrigo Bruno <rfbpb@google.com>
Cr-Commit-Position: refs/heads/master@{#53497}

src/heap/heap.cc

@@ -2246,7 +2246,7 @@ void Heap::ComputeFastPromotionMode() {
       !FLAG_optimize_for_size && FLAG_fast_promotion_new_space &&
       !ShouldReduceMemory() && new_space_->IsAtMaximumCapacity() &&
       survived_in_new_space >= kMinPromotedPercentForFastPromotionMode;
-  if (FLAG_trace_gc_verbose) {
+  if (FLAG_trace_gc_verbose && !FLAG_trace_gc_ignore_scavenger) {
     PrintIsolate(
         isolate(), "Fast promotion mode: %s survival rate: %" PRIuS "%%\n",
         fast_promotion_mode_ ? "true" : "false", survived_in_new_space);