[heap] Test fixes

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 40789c2edc9bef11eaa307d681a2fcf2033c0172..81c4aed7036e82edd3f322dc03532b9c4e07bca0 100644
--- a/test/cctest/heap/test-heap.cc
+++ b/test/cctest/heap/test-heap.cc
@@ -2369,6 +2369,10 @@ static void FillUpNewSpace(NewSpace* new_space) {
 
 
 TEST(GrowAndShrinkNewSpace) {
+  // Avoid shrinking new space in GC epilogue. This can happen if allocation
+  // throughput samples have been taken while executing the benchmark.
+  FLAG_predictable = true;
+
   CcTest::InitializeVM();
   Heap* heap = CcTest::heap();
   NewSpace* new_space = heap->new_space();
@@ -3614,6 +3618,9 @@ TEST(ReleaseOverReservedPages) {
   i::FLAG_page_promotion = false;
   CcTest::InitializeVM();
   Isolate* isolate = CcTest::i_isolate();
+  // If there's snapshot available, we don't know whether 20 small arrays will
+  // fit on the initial pages.
+  if (!isolate->snapshot_available()) return;
   Factory* factory = isolate->factory();
   Heap* heap = isolate->heap();
   v8::HandleScope scope(CcTest::isolate());