[heap] Sort sweep pages list by free memory.

src/heap/spaces.h

Index: src/heap/spaces.h
diff --git a/src/heap/spaces.h b/src/heap/spaces.h
index 532c9b2e878f2cad7e1a3dc3d2c67ae6443d5490..42b8a78b18b302babec6acaf4d78b16b4409650a 100644
--- a/src/heap/spaces.h
+++ b/src/heap/spaces.h
@@ -2116,10 +2116,6 @@ class PagedSpace : public Space {
   // It returns true when sweeping is completed and false otherwise.
   bool EnsureSweeperProgress(intptr_t size_in_bytes);
 
-  void set_end_of_unswept_pages(Page* page) { end_of_unswept_pages_ = page; }
-
-  Page* end_of_unswept_pages() { return end_of_unswept_pages_; }
-
   Page* FirstPage() { return anchor_.next_page(); }
   Page* LastPage() { return anchor_.prev_page(); }