[heap] Fix GrowAndShrinkNewSpace heap test

test/cctest/heap/test-heap.cc

Index: test/cctest/heap/test-heap.cc
diff --git a/test/cctest/heap/test-heap.cc b/test/cctest/heap/test-heap.cc
index 87e9838ea61fe2870c5b4cbdd1394877432d7823..4960c3b7dbde078fcbc54c67335b3aa016b93880 100644
--- a/test/cctest/heap/test-heap.cc
+++ b/test/cctest/heap/test-heap.cc
@@ -2338,6 +2338,10 @@ TEST(GrowAndShrinkNewSpace) {
     return;
   }
 
+  // Make sure we're in a consistent state to start out.
+  CcTest::CollectGarbage(NEW_SPACE);
+  CcTest::CollectGarbage(NEW_SPACE);
+
   // Explicitly growing should double the space capacity.
   size_t old_capacity, new_capacity;
   old_capacity = new_space->TotalCapacity();