Cloning a bunch of stuff from the native_client repository at r6528

ppapi/native_client/src/shared/ppapi_proxy/string_proxy_var.h

Index: ppapi/native_client/src/shared/ppapi_proxy/string_proxy_var.h
===================================================================
--- ppapi/native_client/src/shared/ppapi_proxy/string_proxy_var.h	(revision 0)
+++ ppapi/native_client/src/shared/ppapi_proxy/string_proxy_var.h	(revision 0)
@@ -0,0 +1,48 @@
+// Copyright (c) 2011 The Native Client 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 NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_STRING_PROXY_VAR_H_
+#define NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_STRING_PROXY_VAR_H_
+
+#include "native_client/src/include/nacl_memory.h"
+#include "native_client/src/shared/ppapi_proxy/proxy_var.h"
+
+#include <string>
+
+namespace ppapi_proxy {
+
+// Subclass of ProxyVar that handles string objects.
+class StringProxyVar : public ProxyVar {
+ public:
+  explicit StringProxyVar(const std::string& contents)
+      : ProxyVar(PP_VARTYPE_STRING), contents_(contents) {}
+
+  StringProxyVar(const char* data, size_t len)
+      : ProxyVar(PP_VARTYPE_STRING), contents_(data, len) {}
+
+  const std::string& contents() const { return contents_; }
+
+  // Convenience function to do type checking and down-casting. This returns a
+  // scoped_refptr<>, so you don't have to down-cast the raw pointer.
+  static scoped_refptr<StringProxyVar> CastFromProxyVar(
+      SharedProxyVar proxy_var) {
+    if (proxy_var == NULL || proxy_var->pp_var_type() != PP_VARTYPE_STRING) {
+      scoped_refptr<StringProxyVar> string_var;
+      return string_var;
+    }
+    return scoped_refptr<StringProxyVar>(
+        static_cast<StringProxyVar*>(proxy_var.get()));
+  }
+
+ private:
+  std::string contents_;
+
+  StringProxyVar();  // Not implemented, do not use.
+};
+
+typedef scoped_refptr<StringProxyVar> SharedStringProxyVar;
+
+}  // namespace ppapi_proxy
+
+#endif  // NATIVE_CLIENT_SRC_SHARED_PPAPI_PROXY_STRING_PROXY_VAR_H_