Turn FileDescriptorInfo a collection class

content/public/browser/file_descriptor_info.cc

+// 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.
+
+#include "content/public/browser/file_descriptor_info.h"
+
+namespace content {
+
+FileDescriptorInfo::FileDescriptorInfo() {
+}
+
+FileDescriptorInfo::~FileDescriptorInfo() {
+}
+
+void FileDescriptorInfo::Share(int id, base::PlatformFile fd) {
+  AddToMapping(id, fd);
+}
+
+void FileDescriptorInfo::Transfer(int id, base::ScopedFD fd) {
+  AddToMapping(id, fd.get());
+  owned_descriptors_.push_back(new base::ScopedFD(fd.Pass()));
+}
+
+void FileDescriptorInfo::TransferWithoutMapping(base::ScopedFD fd) {
+  owned_descriptors_.push_back(new base::ScopedFD(fd.Pass()));
+}
+
+base::PlatformFile FileDescriptorInfo::GetFDAt(size_t i) const {
+  return mapping_[i].first;
+}
+
+int FileDescriptorInfo::GetIDAt(size_t i) const {
+  return mapping_[i].second;
+}
+
+void FileDescriptorInfo::AddToMapping(int id, base::PlatformFile fd) {
+  DCHECK(mapping_.end() ==
+         std::find(mapping_.begin(), mapping_.end(), std::make_pair(fd, id)));
+  mapping_.push_back(std::make_pair(fd, id));
+}
+
+const base::FileHandleMappingVector& FileDescriptorInfo::GetMapping() const {
+  return mapping_;
+}
+
+base::FileHandleMappingVector FileDescriptorInfo::GetMappingWithIDAdjustment(
+    int delta) const {
+  base::FileHandleMappingVector result = mapping_;
+  // Adding delta to each ID.
+  for (unsigned i = 0; i < mapping_.size(); ++i)
+    result[i].second += delta;
+  return result;
+}
+
+}  // namespace content