Modify the PPAPI CDM interface to pass more info.

ppapi/proxy/content_decryptor_private_serializer.h

+// Copyright (c) 2012 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_PROXY_CONTENT_DECRYPTOR_PRIVATE_SERIALIZER_H_
+#define PPAPI_PROXY_CONTENT_DECRYPTOR_PRIVATE_SERIALIZER_H_
+
+#include <cstring>
+#include <string>
+
+#include "ppapi/c/private/pp_content_decryptor.h"
+
+namespace ppapi {
+namespace proxy {
+
+// Serialization/deserialization utility functions for storing/extracting
+// PP_{De|En}cryptedBlockInfo structs within std::string's for passing through
+// IPC. Both functions return true upon success, and false upon failure.
+//
+// Note, these functions check the size of |block_info| against the size of
+// the "serialized" data stored within |serialized_block_info|, and will report
+// failure if expectations are not met. Use of CHECK/DCHECK has been avoided
+// because the functions are intended for use on both sides of the IPC proxy.
+
+template <typename T>
+bool SerializeBlockInfo(const T& block_info,
+                        std::string* serialized_block_info) {
+  if (!serialized_block_info)
+    return false;
+
+  serialized_block_info->assign(reinterpret_cast<const char*>(&block_info),
+                                sizeof(block_info));
+
+  if (serialized_block_info->size() != sizeof(block_info))
+    return false;
+
+  return true;
+}
+
+template <typename T>
+bool DeserializeBlockInfo(const std::string& serialized_block_info,
+                          T* block_info) {
+  if (!block_info)
+    return false;
+
+  if (serialized_block_info.size() != sizeof(*block_info))
+    return false;
+
+  std::memcpy(block_info, serialized_block_info.data(), sizeof(*block_info));
+  return true;
+}
+
+}  // namespace proxy
+}  // namespace ppapi
+
+#endif  // PPAPI_PROXY_CONTENT_DECRYPTOR_PRIVATE_SERIALIZER_H_