Inject an ASDataController class to ASTableView, for testing purposes

- Injection can be done via a new internal initializer. The class will be used by ASTableView to create (and configure) a new data controller.
- ASTableViewTests now injects its own type of ASDataController. This facilitates new ways for testing ASTableView-specific behaviours. The first application is counting the number of times relayoutAllNodes is called on the data controller.

AsyncDisplayKit/ASTableViewInternal.h

@@ -0,0 +1,31 @@
+//
+//  ASTableViewInternal.h
+//  AsyncDisplayKit
+//
+//  Created by Huy Nguyen on 26/10/15.
+//  Copyright (c) 2015 Facebook. All rights reserved.
+//
+
+#import "ASTableView.h"
+
+@class ASDataController;
+
+@interface ASTableView (Internal)
+
+@property (nonatomic, retain, readonly) ASDataController *dataController;
+
+/**
+ * Initializer.
+ *
+ * @param frame A rectangle specifying the initial location and size of the table view in its superview’€™s coordinates.
+ * The frame of the table view changes as table cells are added and deleted.
+ *
+ * @param style A constant that specifies the style of the table view. See UITableViewStyle for descriptions of valid constants.
+ *
+ * @param dataControllerClass A controller class injected to and used to create a data controller for the table view.
+ *
+ * @param asyncDataFetchingEnabled This option is reserved for future use, and currently a no-op.
+ */
+- (instancetype)initWithFrame:(CGRect)frame style:(UITableViewStyle)style dataControllerClass:(Class)dataControllerClass asyncDataFetching:(BOOL)asyncDataFetchingEnabled;
+
+@end