Remove uses of base::hash_map from //chrome

chrome/browser/sync_file_system/drive_backend/metadata_database_index.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_H_
 #define CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <map>
 #include <set>
 #include <string>
 #include <unordered_map>
+#include <unordered_set>
 #include <vector>
 
-#include "base/containers/hash_tables.h"
 #include "base/hash.h"
 #include "base/macros.h"
 #include "chrome/browser/sync_file_system/drive_backend/metadata_database_index_interface.h"
 #include "chrome/browser/sync_file_system/drive_backend/tracker_id_set.h"
 
 namespace sync_file_system {
 namespace drive_backend {
 
 class FileMetadata;
 class FileTracker;
 class LevelDBWrapper;
 class ServiceMetadata;
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
-namespace BASE_HASH_NAMESPACE {
+namespace std {
 
 template<> struct hash<sync_file_system::drive_backend::ParentIDAndTitle> {
   std::size_t operator()(
       const sync_file_system::drive_backend::ParentIDAndTitle& v) const {
     return base::HashInts64(v.parent_id, hash<std::string>()(v.title));
   }
 };
 
-}  // namespace BASE_HASH_NAMESPACE
+}  // namespace std
 
 namespace sync_file_system {
 namespace drive_backend {
 
 struct DatabaseContents {
   DatabaseContents();
   ~DatabaseContents();
   std::vector<std::unique_ptr<FileMetadata>> file_metadata;
   std::vector<std::unique_ptr<FileTracker>> file_trackers;
 };
@@ skipping 45 matching lines @@
   int64_t GetLargestChangeID() const override;
   int64_t GetNextTrackerID() const override;
   std::vector<std::string> GetRegisteredAppIDs() const override;
   std::vector<int64_t> GetAllTrackerIDs() const override;
   std::vector<std::string> GetAllMetadataIDs() const override;
 
  private:
   typedef std::unordered_map<std::string, std::unique_ptr<FileMetadata>>
       MetadataByID;
   typedef std::unordered_map<int64_t, std::unique_ptr<FileTracker>> TrackerByID;
-  typedef base::hash_map<std::string, TrackerIDSet> TrackerIDsByFileID;
-  typedef base::hash_map<std::string, TrackerIDSet> TrackerIDsByTitle;
+  typedef std::unordered_map<std::string, TrackerIDSet> TrackerIDsByFileID;
+  typedef std::unordered_map<std::string, TrackerIDSet> TrackerIDsByTitle;
   typedef std::map<int64_t, TrackerIDsByTitle> TrackerIDsByParentAndTitle;
-  typedef base::hash_map<std::string, int64_t> TrackerIDByAppID;
-  typedef base::hash_set<std::string> FileIDSet;
-  typedef base::hash_set<ParentIDAndTitle> PathSet;
+  typedef std::unordered_map<std::string, int64_t> TrackerIDByAppID;
+  typedef std::unordered_set<std::string> FileIDSet;
+  typedef std::unordered_set<ParentIDAndTitle> PathSet;
   typedef std::set<int64_t> DirtyTrackers;
 
   friend class MetadataDatabaseTest;
 
   explicit MetadataDatabaseIndex(LevelDBWrapper* db);
   void Initialize(std::unique_ptr<ServiceMetadata> service_metadata,
                   DatabaseContents* contents);
 
   // Maintains |app_root_by_app_id_|.
   void AddToAppIDIndex(const FileTracker& new_tracker);
@@ skipping 36 matching lines @@
   DirtyTrackers dirty_trackers_;
   DirtyTrackers demoted_dirty_trackers_;
 
   DISALLOW_COPY_AND_ASSIGN(MetadataDatabaseIndex);
 };
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 #endif  // CHROME_BROWSER_SYNC_FILE_SYSTEM_DRIVE_BACKEND_METADATA_DATABASE_INDEX_H_