Revert of [heap] Refactor heap object iteration

src/heap/spaces-inl.h

Index: src/heap/spaces-inl.h
diff --git a/src/heap/spaces-inl.h b/src/heap/spaces-inl.h
index eefbc711757b2d106e824986e6f411d3c652e8c9..1567a8790d26ce5d0c88bd86847299cca5985fdf 100644
--- a/src/heap/spaces-inl.h
+++ b/src/heap/spaces-inl.h
@@ -28,14 +28,10 @@
   return tmp;
 }
 
-PageRange::PageRange(Address start, Address limit)
-    : begin_(Page::FromAllocationAreaAddress(start)),
-      end_(Page::FromAllocationAreaAddress(limit)->next_page()) {
-#ifdef DEBUG
-  if (begin_->InNewSpace()) {
-    SemiSpace::AssertValidRange(start, limit);
-  }
-#endif  // DEBUG
+NewSpacePageRange::NewSpacePageRange(Address start, Address limit)
+    : range_(Page::FromAddress(start),
+             Page::FromAllocationAreaAddress(limit)->next_page()) {
+  SemiSpace::AssertValidRange(start, limit);
 }
 
 // -----------------------------------------------------------------------------
@@ -72,14 +68,8 @@
 
 HeapObject* HeapObjectIterator::FromCurrentPage() {
   while (cur_addr_ != cur_end_) {
-    // When the current address equals top we have to handle two scenarios:
-    // - Old space page: Move forward to limit if top != limit. We will find
-    //   a filler following limit.
-    // - New space page: We have to stop iteration before the linear allocation
-    //   area as there are no fillers behind it.
-    if (cur_addr_ == space_->top() &&
-        (cur_addr_ != space_->limit() || current_page()->InNewSpace())) {
-      cur_addr_ = current_page()->InNewSpace() ? cur_end_ : space_->limit();
+    if (cur_addr_ == space_->top() && cur_addr_ != space_->limit()) {
+      cur_addr_ = space_->limit();
       continue;
     }
     HeapObject* obj = HeapObject::FromAddress(cur_addr_);
@@ -89,7 +79,7 @@
     if (!obj->IsFiller()) {
       if (obj->IsCode()) {
         DCHECK_EQ(space_, space_->heap()->code_space());
-        DCHECK_CODEOBJECT_SIZE(obj_size, reinterpret_cast<PagedSpace*>(space_));
+        DCHECK_CODEOBJECT_SIZE(obj_size, space_);
       } else {
         DCHECK_OBJECT_SIZE(obj_size);
       }