Fix memory leaks in ~Zone and ~Isolate

src/serialize.h

Index: src/serialize.h
diff --git a/src/serialize.h b/src/serialize.h
index f8282f652994fa10f752049f0efcba04f725db28..66d6fb5111ea45c2f7ecf7b1d5fed7003fd9169c 100644
--- a/src/serialize.h
+++ b/src/serialize.h
@@ -60,6 +60,52 @@ const int kDebugRegisterBits = 4;
 const int kDebugIdShift = kDebugRegisterBits;
 
 
+// ExternalReferenceTable is a helper class that defines the relationship
+// between external references and their encodings. It is used to build
+// hashmaps in ExternalReferenceEncoder and ExternalReferenceDecoder.
+class ExternalReferenceTable {
+ public:
+  static ExternalReferenceTable* instance(Isolate* isolate);
+
+  ~ExternalReferenceTable() { }
+
+  int size() const { return refs_.length(); }
+
+  Address address(int i) { return refs_[i].address; }
+
+  uint32_t code(int i) { return refs_[i].code; }
+
+  const char* name(int i) { return refs_[i].name; }
+
+  int max_id(int code) { return max_id_[code]; }
+
+ private:
+  explicit ExternalReferenceTable(Isolate* isolate) : refs_(64) {
+      PopulateTable(isolate);
+  }
+
+  struct ExternalReferenceEntry {
+    Address address;
+    uint32_t code;
+    const char* name;
+  };
+
+  void PopulateTable(Isolate* isolate);
+
+  // For a few types of references, we can get their address from their id.
+  void AddFromId(TypeCode type,
+                 uint16_t id,
+                 const char* name,
+                 Isolate* isolate);
+
+  // For other types of references, the caller will figure out the address.
+  void Add(Address address, TypeCode type, uint16_t id, const char* name);
+
+  List<ExternalReferenceEntry> refs_;
+  int max_id_[kTypeCodeCount];
+};
+
+
 class ExternalReferenceEncoder {
  public:
   ExternalReferenceEncoder();