Upstream ios/showcase source code.

ios/showcase/common/coordinator.h

+// Copyright 2016 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 IOS_SHOWCASE_COMMON_COORDINATOR_H_
+#define IOS_SHOWCASE_COMMON_COORDINATOR_H_
+
+#import <Foundation/Foundation.h>
+
+// This protocol is the common interface to the simple non-production
+// coordinators that will initialize, set up and present production view
+// controllers, usually with completely mocked data.
+@protocol Coordinator<NSObject>
+
+// The base view controller used to present the view controller that this
+// coordinator drives.
+@property(nonatomic, weak) UIViewController* baseViewController;
+
+// Typically, this initializes a view controller, sets it up and presents it.
+- (void)start;
+
+@end
+
+#endif  // IOS_SHOWCASE_COMMON_COORDINATOR_H_