[heap] Decouple old generation allocation limit from external memory.

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 9908f5c938bcc044adc6bae7f1600d9899a4c868..966b8c7bb104419cb469d9b6759f8b16c309a909 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -1102,7 +1102,7 @@ void IncrementalMarking::SpeedUp() {
   }
 
   bool size_of_old_space_multiplied_by_n_during_marking =
-      (heap_->PromotedTotalSize() >
+      (heap_->PromotedSpaceSizeOfObjects() >
        (marking_speed_ + 1) *
            old_generation_space_used_at_start_of_incremental_);
   if (size_of_old_space_multiplied_by_n_during_marking) {
@@ -1115,7 +1115,7 @@ void IncrementalMarking::SpeedUp() {
   }
 
   int64_t promoted_during_marking =
-      heap_->PromotedTotalSize() -
+      heap_->PromotedSpaceSizeOfObjects() -
       old_generation_space_used_at_start_of_incremental_;
   intptr_t delay = marking_speed_ * MB;
   intptr_t scavenge_slack = heap_->MaxSemiSpaceSize();
@@ -1290,7 +1290,7 @@ void IncrementalMarking::ResetStepCounters() {
   old_generation_space_available_at_start_of_incremental_ =
       SpaceLeftInOldSpace();
   old_generation_space_used_at_start_of_incremental_ =
-      heap_->PromotedTotalSize();
+      heap_->PromotedSpaceSizeOfObjects();
   bytes_rescanned_ = 0;
   marking_speed_ = kInitialMarkingSpeed;
   bytes_scanned_ = 0;