Refactor CdmPromise and related classes

media/base/cdm_callback_promise.cc

+// Copyright 2014 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 "media/base/cdm_callback_promise.h"
+
+#include "base/logging.h"
+
+namespace media {
+
+template <typename... T>
+CdmCallbackPromise<T...>::CdmCallbackPromise(
+    const base::Callback<void(const T&...)>& resolve_cb,
+    const PromiseRejectedCB& reject_cb)
+    : resolve_cb_(resolve_cb), reject_cb_(reject_cb) {
+  DCHECK(!resolve_cb_.is_null());
+  DCHECK(!reject_cb_.is_null());
+}
+
+template <typename... T>
+CdmCallbackPromise<T...>::~CdmCallbackPromise() {
+}
+
+template <typename... T>
+void CdmCallbackPromise<T...>::resolve(const T&... result) {
+  MarkPromiseSettled();
+  resolve_cb_.Run(result...);
+}
+
+template <typename... T>
+void CdmCallbackPromise<T...>::reject(MediaKeys::Exception exception_code,
+                                      uint32 system_code,
+                                      const std::string& error_message) {
+  MarkPromiseSettled();
+  reject_cb_.Run(exception_code, system_code, error_message);
+}
+
+// Explicit template instantiation for the Promises needed.
+template class MEDIA_EXPORT CdmCallbackPromise<>;
+template class MEDIA_EXPORT CdmCallbackPromise<std::string>;
+template class MEDIA_EXPORT CdmCallbackPromise<KeyIdsVector>;
+
+}  // namespace media