Reworked the Share Extension to use a subclass of MXKRecentsDataSource to show content, solved the room order issue, as well introduced a new class ShareExtensionManager responsible for Sharing content and communicating with the system to terminate the extension with the appropriate exit code when needed.

RiotShareExtension/Model/ShareExtensionManager.h

@@ -0,0 +1,24 @@
+//
+//  ShareExtensionManager.h
+//  Riot
+//
+//  Created by Aram Sargsyan on 8/10/17.
+//  Copyright © 2017 matrix.org. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+#import <MatrixKit/MatrixKit.h>
+
+@interface ShareExtensionManager : NSObject
+
+@property NSExtensionContext *shareExtensionContext;
+
++ (instancetype)sharedManager;
+
+- (void)sendContentToRoom:(MXRoom *)room failureBlock:(void(^)())failureBlock;
+
+- (void)cancelSharing;
+
+- (void)cancelSharingWithFailure;
+
+@end