Add PPB_VarDictionary_Dev support - part 1.

ppapi/shared_impl/var_value_conversions.h

+// Copyright (c) 2013 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_SHARED_IMPL_VAR_VALUE_CONVERSIONS_H_
+#define PPAPI_SHARED_IMPL_VAR_VALUE_CONVERSIONS_H_
+
+#include "ppapi/c/pp_var.h"
+#include "ppapi/shared_impl/ppapi_shared_export.h"
+
+namespace base {
+class Value;
+}
+
+namespace ppapi {
+
+// Converts a PP_Var to a base::Value object. The caller takes ownership of the
+// returned object.
+//
+// Both PP_VARTYPE_UNDEFINED and PP_VARTYPE_NULL are converted to
+// base::Value::TYPE_NULL. In dictionary vars, key-value pairs whose value is
+// undefined (PP_VARTYPE_UNDEFINED) are ignored. If a node in |var| appears more
+// than once, it is duplicated in the result. For example, if |var| is an array
+// and it has two elements pointing to the same dictionary, the resulting list
+// value will have two copies of the dictionary.
+//
+// The conversion fails and returns NULL if
+// - |var| is object (PP_VARTYPE_OBJECT); or
+// - |var| is an array or dictionary, and calling CreateValueFromVar() on any of
+//   the array elements or dictionary values fails; or
+// - there exist circular references, i.e., an array or dictionary is its own
+//   ancestor/descendant.
+PPAPI_SHARED_EXPORT base::Value* CreateValueFromVar(const PP_Var& var);
+
+// The returned var has been added ref on behalf of the caller.
+// Returns an undefined var if the conversion fails.
+PPAPI_SHARED_EXPORT PP_Var CreateVarFromValue(const base::Value& value);
+
+}  // namespace ppapi
+
+#endif  // PPAPI_SHARED_IMPL_VAR_VALUE_CONVERSIONS_H_