Add initial Controller to DownloadService

components/download/internal/entry_utils.h

Index: components/download/internal/entry_utils.h
diff --git a/components/download/internal/entry_utils.h b/components/download/internal/entry_utils.h
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+++ b/components/download/internal/entry_utils.h
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+// Copyright 2017 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 COMPONENTS_DOWNLOAD_INTERNAL_ENTRY_UTILS_H_
+#define COMPONENTS_DOWNLOAD_INTERNAL_ENTRY_UTILS_H_
+
+#include <map>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "components/download/public/clients.h"
+
+namespace download {
+
+struct Entry;
+
+namespace util {
+
+// Helper method to return the number of Entry objects in |entries| are
+// associated with |client|.
+uint32_t GetNumberOfEntriesForClient(DownloadClient client,
+                                     const std::vector<Entry*>& entries);
+
+// Effectively runs a map reduce to turn a list of Entry objects into a map of
+// [Client Id] -> List of entries.  Any Entry in |entries| that does not have a
+// matching DownloadClient in |clients| will be put in the
+// DownloadClient::INVALID bucket.
+std::map<DownloadClient, std::vector<std::string>> MapReduceEntriesToClients(
+    const std::set<DownloadClient>& clients,
+    const std::vector<Entry*>& entries);
+
+}  // namespace util
+}  // namespace download
+
+#endif  // COMPONENTS_DOWNLOAD_INTERNAL_ENTRY_UTILS_H_