Simplifying GC heuristics, deleted old generation limit factor.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index add42c01d6f499a2996ee1872bcb39c4a1f4e178..57f57c4b5df48853461e317be1227c56695ecfff 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1567,7 +1567,6 @@ class Heap {
     intptr_t limit =
         Max(old_gen_size + old_gen_size / divisor, kMinimumPromotionLimit);
     limit += new_space_.Capacity();
-    limit *= old_gen_limit_factor_;
     intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
     return Min(limit, halfway_to_the_max);
   }
@@ -1578,7 +1577,6 @@ class Heap {
     intptr_t limit =
         Max(old_gen_size + old_gen_size / divisor, kMinimumAllocationLimit);
     limit += new_space_.Capacity();
-    limit *= old_gen_limit_factor_;
     intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
     return Min(limit, halfway_to_the_max);
   }
@@ -1998,10 +1996,6 @@ class Heap {
   // every allocation in large object space.
   intptr_t old_gen_allocation_limit_;
 
-  // Sometimes the heuristics dictate that those limits are increased.  This
-  // variable records that fact.
-  int old_gen_limit_factor_;
-
   // Used to adjust the limits that control the timing of the next GC.
   intptr_t size_of_old_gen_at_last_old_space_gc_;