[heap] Don't use black pages for map, code and, lo space. Instead color objects black.

src/heap/incremental-marking.cc

Index: src/heap/incremental-marking.cc
diff --git a/src/heap/incremental-marking.cc b/src/heap/incremental-marking.cc
index 686c6738821437a1621c4f495391632813ae58e3..a3de6a13ad749d51fbe636201e1e6ef41d28755c 100644
--- a/src/heap/incremental-marking.cc
+++ b/src/heap/incremental-marking.cc
@@ -571,12 +571,9 @@ void IncrementalMarking::StartBlackAllocation() {
   DCHECK(FLAG_black_allocation);
   DCHECK(IsMarking());
   black_allocation_ = true;
-  PagedSpaces spaces(heap());
-  for (PagedSpace* space = spaces.next(); space != NULL;
-       space = spaces.next()) {
-    space->EmptyAllocationInfo();
-    space->free_list()->Reset();
-  }
+  OldSpace* old_space = heap()->old_space();
+  old_space->EmptyAllocationInfo();
+  old_space->free_list()->Reset();
   if (FLAG_trace_incremental_marking) {
     PrintF("[IncrementalMarking] Black allocation started\n");
   }