Fix logic for doing incremental marking steps on tenured allocation.

src/heap/incremental-marking.cc

Index: src/heap/incremental-marking.cc
diff --git a/src/heap/incremental-marking.cc b/src/heap/incremental-marking.cc
index dfcd68a3d34326388682265bf937aadf340991c3..d854bfbc7cd361eeb2e3f7235e931ee0930ecdd5 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -821,7 +821,7 @@ void IncrementalMarking::OldSpaceStep(intptr_t allocated) {
   if (IsStopped() && ShouldActivate()) {
     Start();
   } else {
-    Step(allocated * kFastMarking / kInitialMarkingSpeed, GC_VIA_STACK_GUARD);
+    Step(allocated * kOldSpaceAllocationMarkingFactor, GC_VIA_STACK_GUARD);
   }
 }
 
@@ -897,8 +897,7 @@ intptr_t IncrementalMarking::Step(intptr_t allocated_bytes,
                                   ForceMarkingAction marking,
                                   ForceCompletionAction completion) {
   if (heap_->gc_state() != Heap::NOT_IN_GC || !FLAG_incremental_marking ||
-      !FLAG_incremental_marking_steps ||
-      (state_ != SWEEPING && state_ != MARKING)) {
+      !CanDoSteps()) {
     return 0;
   }