Tweaks to PPB_VarArrayBuffer in preperation for taking out of Dev.

ppapi/cpp/var.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef PPAPI_CPP_VAR_H_
 #define PPAPI_CPP_VAR_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 74 matching lines @@
   Var(const Var& other);
 
   /// Destructor.
   virtual ~Var();
 
   /// This function assigns one <code>Var</code> to another <code>Var</code>.
   ///
   /// @param[in] other The <code>Var</code> to be assigned.
   ///
   /// @return A resulting <code>Var</code>.
-  Var& operator=(const Var& other);
+  virtual Var& operator=(const Var& other);
 
   /// This function compares object identity (rather than value identity) for
   /// objects, dictionaries, and arrays
   ///
   /// @param[in] other The <code>Var</code> to be compared to this Var.
   ///
   /// @return true if the <code>other</code> <code>Var</code> is the same as
   /// this <code>Var</code>, otherwise false.
   bool operator==(const Var& other) const;
 
@@ skipping 185 matching lines @@
  private:
   // Prevent an arbitrary pointer argument from being implicitly converted to
   // a bool at Var construction. If somebody makes such a mistake, (s)he will
   // get a compilation error.
   Var(void* non_scriptable_object_pointer);
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_VAR_H_