[Isolates] Merge 7201:7258 from bleeding_edge to isolates.

src/mark-compact.h

Index: src/mark-compact.h
===================================================================
--- src/mark-compact.h	(revision 7254)
+++ src/mark-compact.h	(working copy)
@@ -285,11 +285,14 @@
   // group marked.
   void MarkObjectGroups();
 
-  // Mark all objects in an object group with at least one marked
-  // object, then all objects reachable from marked objects in object
-  // groups, and repeat.
-  void ProcessObjectGroups();
+  // Mark objects in implicit references groups if their parent object
+  // is marked.
+  void MarkImplicitRefGroups();
 
+  // Mark all objects which are reachable due to host application
+  // logic like object groups or implicit references' groups.
+  void ProcessExternalMarking();
+
   // Mark objects reachable (transitively) from objects in the marking stack
   // or overflowed in the heap.
   void ProcessMarkingStack();