[Examples, Build] Moving some smaller / less useful examples to a separate directory, speeding up builds.

examples_extra/SynchronousConcurrency/Sample/AsyncViewController.m

@@ -0,0 +1,37 @@
+//
+//  AsyncViewController.m
+//  Sample
+//
+//  Created by Scott Goodson on 9/26/15.
+//  Copyright © 2015 Facebook. All rights reserved.
+//
+
+#import "AsyncViewController.h"
+#import "RandomCoreGraphicsNode.h"
+
+@implementation AsyncViewController
+
+- (instancetype)init
+{
+  if (!(self = [super initWithNode:[[RandomCoreGraphicsNode alloc] init]])) {
+    return nil;
+  }
+
+  self.neverShowPlaceholders = YES;
+  self.tabBarItem = [[UITabBarItem alloc] initWithTabBarSystemItem:UITabBarSystemItemFavorites tag:0];
+  return self;
+}
+
+- (void)viewWillAppear:(BOOL)animated
+{
+  // FIXME: This is only being called on the first time the UITabBarController shows us.
+  [super viewWillAppear:animated];
+}
+
+- (void)viewDidDisappear:(BOOL)animated
+{
+  [self.node recursivelyClearContents];
+  [super viewDidDisappear:animated];
+}
+
+@end