Calculates retaining paths through user fields and ignores VM objects

runtime/vm/raw_object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_RAW_OBJECT_H_
 #define RUNTIME_VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/atomic.h"
 #include "vm/exceptions.h"
@@ skipping 671 matching lines @@
   friend class Instance;                // StorePointer
   friend class StackFrame;              // GetCodeObject assertion.
   friend class CodeLookupTableBuilder;  // profiler
   friend class NativeEntry;             // GetClassId
   friend class WritePointerVisitor;     // GetClassId
   friend class Simulator;
   friend class SimulatorHelpers;
   friend class ObjectLocator;
   friend class InstanceMorpher;  // GetClassId
   friend class VerifyCanonicalVisitor;
+  friend class ObjectGraph::Stack;  // GetClassId
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(RawObject);
 };
 
 class RawClass : public RawObject {
  public:
   enum ClassFinalizedState {
     kAllocated = 0,         // Initial state.
     kPreFinalized,          // VM classes: size precomputed, but no checks done.
@@ skipping 1736 matching lines @@
   COMPILE_ASSERT(kExternalTypedDataInt8ArrayCid ==
                  kTypedDataInt8ArrayViewCid + 15);
   COMPILE_ASSERT(kByteBufferCid == kExternalTypedDataInt8ArrayCid + 14);
   COMPILE_ASSERT(kNullCid == kByteBufferCid + 1);
   return (kNullCid - kTypedDataInt8ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_RAW_OBJECT_H_