Expose last seen heap object id via v8 public api.

src/api.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 6211 matching lines @@
 }
 
 
 void HeapProfiler::StopHeapObjectsTracking() {
   i::Isolate* isolate = i::Isolate::Current();
   IsDeadCheck(isolate, "v8::HeapProfiler::StopHeapObjectsTracking");
   i::HeapProfiler::StopHeapObjectsTracking();
 }
 
 
-void HeapProfiler::PushHeapObjectsStats(OutputStream* stream) {
+SnapshotObjectId HeapProfiler::PushHeapObjectsStats(OutputStream* stream) {
   i::Isolate* isolate = i::Isolate::Current();
   IsDeadCheck(isolate, "v8::HeapProfiler::PushHeapObjectsStats");
   return i::HeapProfiler::PushHeapObjectsStats(stream);
 }
 
 
 void HeapProfiler::DeleteAllSnapshots() {
   i::Isolate* isolate = i::Isolate::Current();
   IsDeadCheck(isolate, "v8::HeapProfiler::DeleteAllSnapshots");
   i::HeapProfiler::DeleteAllSnapshots();
@@ skipping 139 matching lines @@
 
 
 char* HandleScopeImplementer::Iterate(ObjectVisitor* v, char* storage) {
   HandleScopeImplementer* scope_implementer =
       reinterpret_cast<HandleScopeImplementer*>(storage);
   scope_implementer->IterateThis(v);
   return storage + ArchiveSpacePerThread();
 }
 
 } }  // namespace v8::internal