Add method for resolving SnapshotObjectId by given object

src/profile-generator.cc

Index: src/profile-generator.cc
===================================================================
--- src/profile-generator.cc	(revision 11329)
+++ src/profile-generator.cc	(working copy)
@@ -1366,7 +1366,6 @@
   if (entry == NULL) return 0;
   int entry_index = static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
   EntryInfo& entry_info = entries_->at(entry_index);
-  entry_info.accessed = true;

[yurys, 2012/04/16 13:04:38]

HeapObjectsMap::FindEntry is only called by
HeapSnapshotsCollection::FindHeapObjectById and the new
HeapSnapshotsCollection::FindObjectId methods. In both cases we shouldn't update
the flag.

   ASSERT(static_cast<uint32_t>(entries_->length()) > entries_map_.occupancy());
   return entry_info.id;
 }