Align base::hash_map with C++11.

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 <map>
 #include <set>
 #include <string>
@@ skipping 11 matching lines @@
 class FileMetadata;
 class FileTracker;
 class LevelDBWrapper;
 class ServiceMetadata;
 
 }  // namespace drive_backend
 }  // namespace sync_file_system
 
 namespace BASE_HASH_NAMESPACE {
 
-#if defined(COMPILER_GCC)
 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));
   }
 };
-#elif defined(COMPILER_MSVC)
-inline size_t hash_value(
-    const sync_file_system::drive_backend::ParentIDAndTitle& v) {
-  return base::HashInts64(v.parent_id, hash_value(v.title));
-}
-#endif  // COMPILER
 
 }  // namespace BASE_HASH_NAMESPACE
 
 namespace sync_file_system {
 namespace drive_backend {
 
 struct DatabaseContents {
   DatabaseContents();
   ~DatabaseContents();
   ScopedVector<FileMetadata> file_metadata;
@@ skipping 105 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_