Refactor storage of global handles.

src/heap.cc

Index: src/heap.cc
diff --git a/src/heap.cc b/src/heap.cc
index aa728fd051acef5e96d6ddb4ec45a99f6af57e6b..5355069f89a6fd709324af016f72aa2854cc5cd2 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -1060,9 +1060,10 @@ void Heap::Scavenge() {
   scavenge_visitor.VisitPointer(BitCast<Object**>(&global_contexts_list_));
 
   new_space_front = DoScavenge(&scavenge_visitor, new_space_front);
-  isolate_->global_handles()->IdentifyWeakIndependentHandles(
+  isolate_->global_handles()->IdentifyNewSpaceWeakIndependentHandles(
       &IsUnscavengedHeapObject);
-  isolate_->global_handles()->IterateWeakIndependentRoots(&scavenge_visitor);
+  isolate_->global_handles()->IterateNewSpaceWeakIndependentRoots(
+      &scavenge_visitor);
   new_space_front = DoScavenge(&scavenge_visitor, new_space_front);
 
 
@@ -4599,7 +4600,7 @@ void Heap::IterateStrongRoots(ObjectVisitor* v, VisitMode mode) {
       isolate_->global_handles()->IterateStrongRoots(v);
       break;
     case VISIT_ALL_IN_SCAVENGE:
-      isolate_->global_handles()->IterateStrongAndDependentRoots(v);
+      isolate_->global_handles()->IterateNewSpaceStrongAndDependentRoots(v);
       break;
     case VISIT_ALL_IN_SWEEP_NEWSPACE:
     case VISIT_ALL: