[PPAPI] Added VarResource_Dev class.

ppapi/cpp/dev/var_resource_dev.cc

+// Copyright 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.
+
+#include "ppapi/cpp/dev/var_resource_dev.h"
+
+#include "ppapi/c/dev/ppb_var_resource_dev.h"
+#include "ppapi/cpp/logging.h"
+#include "ppapi/cpp/module_impl.h"
+
+namespace pp {
+
+namespace {
+
+template <> const char* interface_name<PPB_VarResource_Dev_0_1>() {
+  return PPB_VAR_RESOURCE_DEV_INTERFACE_0_1;
+}
+
+}  // namespace
+
+VarResource_Dev::VarResource_Dev(const pp::Resource& resource) : Var(Null()) {
+  if (!has_interface<PPB_VarResource_Dev_0_1>()) {
+    PP_NOTREACHED();
+    return;
+  }
+
+  // Note: Var(Null()) sets is_managed_ to true, so |var_| will be properly
+  // released upon destruction.
+  var_ = get_interface<PPB_VarResource_Dev_0_1>()->VarFromResource(
+      resource.pp_resource());
+}
+
+VarResource_Dev::VarResource_Dev(const Var& var) : Var(var) {
+  if (!var.is_resource()) {
+    PP_NOTREACHED();
+
+    // This takes care of releasing the reference that this object holds.
+    Var::operator=(Var(Null()));
+  }
+}
+
+VarResource_Dev::VarResource_Dev(const VarResource_Dev& other) : Var(other) {}
+
+VarResource_Dev::~VarResource_Dev() {}
+
+VarResource_Dev& VarResource_Dev::operator=(const VarResource_Dev& other) {
+  Var::operator=(other);
+  return *this;
+}
+
+Var& VarResource_Dev::operator=(const Var& other) {
+  if (other.is_resource()) {
+    Var::operator=(other);
+  } else {
+    PP_NOTREACHED();
+    Var::operator=(Var(Null()));
+  }
+  return *this;
+}
+
+pp::Resource VarResource_Dev::AsResource() {
+  if (!has_interface<PPB_VarResource_Dev_0_1>())
+    return pp::Resource();
+
+  return pp::Resource(
+      pp::PASS_REF,
+      get_interface<PPB_VarResource_Dev_0_1>()->VarToResource(var_));
+}
+
+}  // namespace pp