Grow small old generation faster.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 3a1f4560f13c5554aa200be560d5af1841c79241..0f87fd1de8c9e9e09202d20de28a11e5ef2cd11e 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -1524,10 +1524,9 @@ class Heap {
       8 * (Page::kPageSize > MB ? Page::kPageSize : MB);
 
   intptr_t OldGenerationAllocationLimit(intptr_t old_gen_size) {
-    const int divisor = FLAG_stress_compaction ? 10 : 1;
-    intptr_t limit =
-        Max(old_gen_size + old_gen_size / divisor,
-            kMinimumOldGenerationAllocationLimit);
+    intptr_t limit = FLAG_stress_compaction ?
+        old_gen_size + old_gen_size / 10 : old_gen_size * 4;
+    limit = Max(limit, kMinimumOldGenerationAllocationLimit);
     limit += new_space_.Capacity();
     intptr_t halfway_to_the_max = (old_gen_size + max_old_generation_size_) / 2;
     return Min(limit, halfway_to_the_max);