[heap] Modernize all *Page iterators to be proper C++ iterators

test/cctest/heap/heap-utils.cc

Index: test/cctest/heap/heap-utils.cc
diff --git a/test/cctest/heap/heap-utils.cc b/test/cctest/heap/heap-utils.cc
index 8abc5c3b5c63d2e863080effda3d2c0a69a2396a..7d4d4bf40dc31d4d267ab6df5c3e7f18354a2078 100644
--- a/test/cctest/heap/heap-utils.cc
+++ b/test/cctest/heap/heap-utils.cc
@@ -18,10 +18,8 @@ void SealCurrentObjects(Heap* heap) {
   heap->CollectAllGarbage();
   heap->CollectAllGarbage();
   heap->mark_compact_collector()->EnsureSweepingCompleted();
-  PageIterator it(heap->old_space());
   heap->old_space()->EmptyAllocationInfo();
-  while (it.has_next()) {
-    Page* page = it.next();
+  for (Page* page : *heap->old_space()) {
     page->MarkNeverAllocateForTesting();
   }
 }
@@ -143,9 +141,8 @@ void SimulateFullSpace(v8::internal::PagedSpace* space) {
 
 void AbandonCurrentlyFreeMemory(PagedSpace* space) {
   space->EmptyAllocationInfo();
-  PageIterator pit(space);
-  while (pit.has_next()) {
-    pit.next()->MarkNeverAllocateForTesting();
+  for (Page* page : *space) {
+    page->MarkNeverAllocateForTesting();
   }
 }