Reland v5 of Sessions Refactor

components/sync_sessions/synced_window_delegates_getter.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 COMPONENTS_SYNC_SESSIONS_SYNCED_WINDOW_DELEGATES_GETTER_H_
 #define COMPONENTS_SYNC_SESSIONS_SYNCED_WINDOW_DELEGATES_GETTER_H_
 
-#include <set>
+#include <map>
 
 #include "base/macros.h"
 #include "components/sessions/core/session_id.h"
 
 namespace sync_sessions {
 
 class SyncedWindowDelegate;
 
 // An interface for accessing SyncedWindowDelegates. Subclasses define
 // how this is done on different platforms.
 class SyncedWindowDelegatesGetter {
  public:
+  using SyncedWindowDelegateMap =
+      std::map<SessionID::id_type, const SyncedWindowDelegate*>;
+
   SyncedWindowDelegatesGetter();
   virtual ~SyncedWindowDelegatesGetter();
 
   // Returns all SyncedWindowDelegate instances.
-  virtual std::set<const SyncedWindowDelegate*> GetSyncedWindowDelegates() = 0;
+  virtual SyncedWindowDelegateMap GetSyncedWindowDelegates() = 0;
 
   // Find a SyncedWindowDelegate given its window's id.
   virtual const SyncedWindowDelegate* FindById(SessionID::id_type id) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SyncedWindowDelegatesGetter);
 };
 
 }  // namespace sync_sessions
 
 #endif  // COMPONENTS_SYNC_SESSIONS_SYNCED_WINDOW_DELEGATES_GETTER_H_