Connect heap map to instance view.

runtime/vm/service.cc

Index: runtime/vm/service.cc
===================================================================
--- runtime/vm/service.cc	(revision 35144)
+++ runtime/vm/service.cc	(working copy)
@@ -1585,6 +1585,10 @@
   virtual uword filter_addr() const { return addr_; }
 
   virtual bool FindObject(RawObject* obj) const {
+    // Free list elements are not real objects, so skip them.
+    if (obj->IsFreeListElement()) {
+      return false;
+    }
     uword obj_begin = RawObject::ToAddr(obj);
     uword obj_end = obj_begin + obj->Size();
     return obj_begin <= addr_ && addr_ < obj_end;