Add method for resolving SnapshotObjectId by given object

src/profile-generator.h

Index: src/profile-generator.h
===================================================================
--- src/profile-generator.h	(revision 11329)
+++ src/profile-generator.h	(working copy)
@@ -788,6 +788,9 @@
   StringsStorage* names() { return &names_; }
   TokenEnumerator* token_enumerator() { return token_enumerator_; }
 
+  SnapshotObjectId FindObjectId(Address object_addr) {
+    return ids_.FindEntry(object_addr);
+  }
   SnapshotObjectId GetObjectId(Address object_addr, int object_size) {
     return ids_.FindOrAddEntry(object_addr, object_size);
   }