diff --git a/src/utils.h b/src/utils.h
index b89f284..da7a1d9 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -1,4 +1,4 @@
-// Copyright 2006-2008 the V8 project authors. All rights reserved.
+// Copyright 2011 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:
@@ -222,6 +222,11 @@
     return static_cast<uint32_t>(value) << shift;
   }
 
+  // Returns a uint32_t with the bit field value updated.
+  static uint32_t update(uint32_t previous, T value) {
+    return (previous & ~mask()) | encode(value);
+  }
+
   // Extracts the bit field from the value.
   static T decode(uint32_t value) {
     return static_cast<T>((value & mask()) >> shift);
@@ -251,6 +256,12 @@
 }
 
 
+static inline uint32_t ComputePointerHash(void* ptr) {
+  return ComputeIntegerHash(
+      static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr)));
+}
+
+
 // ----------------------------------------------------------------------------
 // Miscellaneous
 
@@ -576,14 +587,7 @@
   }
 
   // Resets the collector to be empty.
-  virtual void Reset() {
-    for (int i = chunks_.length() - 1; i >= 0; i--) {
-      chunks_.at(i).Dispose();
-    }
-    chunks_.Rewind(0);
-    index_ = 0;
-    size_ = 0;
-  }
+  virtual void Reset();
 
   // Total number of elements added to collector so far.
   inline int size() { return size_; }