[heap] Sort sweep pages list by free memory.

src/heap/mark-compact-inl.h

Index: src/heap/mark-compact-inl.h
diff --git a/src/heap/mark-compact-inl.h b/src/heap/mark-compact-inl.h
index a59d36bfa1c463a4ecdd23caa683c98ec14dd7d9..bc41a1773cf21b30f5a9df8d3f34762cf0c11397 100644
--- a/src/heap/mark-compact-inl.h
+++ b/src/heap/mark-compact-inl.h
@@ -12,6 +12,18 @@
 namespace v8 {
 namespace internal {
 
+inline std::vector<Page*>& MarkCompactCollector::sweeping_list(Space* space) {
+  if (space == heap()->old_space()) {
+    return sweeping_list_old_space_;
+  } else if (space == heap()->code_space()) {
+    return sweeping_list_code_space_;
+  } else if (space == heap()->map_space()) {
+    return sweeping_list_map_space_;
+  }
+  UNREACHABLE();
+}
+
+
 void MarkCompactCollector::PushBlack(HeapObject* obj) {
   DCHECK(Marking::IsBlack(Marking::MarkBitFrom(obj)));
   if (marking_deque_.Push(obj)) {