Reland v5 of Sessions Refactor

components/sync_sessions/synced_window_delegates_getter.h

Index: components/sync_sessions/synced_window_delegates_getter.h
diff --git a/components/sync_sessions/synced_window_delegates_getter.h b/components/sync_sessions/synced_window_delegates_getter.h
index 35e8f1c3cb9ca92de84106cf3f0de83d935d4e4b..303e4fd97662f4638cfd7282bf04ccf8635f8c13 100644
--- a/components/sync_sessions/synced_window_delegates_getter.h
+++ b/components/sync_sessions/synced_window_delegates_getter.h
@@ -5,7 +5,7 @@
 #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"
@@ -18,11 +18,14 @@ class SyncedWindowDelegate;
 // 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;