[heap] ExternalStringTable: Separate Iterate and CleanUp methods

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 015da615b2786f7ccfaf5f296a0384fb05fb30df..9cdde5bcf0da4e504e8da35e85b3aa090e6d3e7f 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -1513,11 +1513,13 @@ class Heap {
     // Registers an external string.
     inline void AddString(String* string);
 
-    inline void Iterate(ObjectVisitor* v);
+    inline void IterateAll(ObjectVisitor* v);
+    inline void IterateNewSpaceStrings(ObjectVisitor* v);
 
-    // Restores internal invariant and gets rid of collected strings.
-    // Must be called after each Iterate() that modified the strings.
-    void CleanUp();
+    // Restores internal invariant and gets rid of collected strings. Must be
+    // called after each Iterate*() that modified the strings.
+    void CleanUpAll();
+    void CleanUpNewSpaceStrings();
 
     // Destroys all allocated memory.
     void TearDown();