[MacViews] Enable dragging a window by its caption/draggable areas.

ui/base/test/windowed_nsnotification_observer.h

+// Copyright 2015 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 UI_BASE_TEST_WINDOWED_NSNOTIFICATION_OBSERVER_H_
+#define UI_BASE_TEST_WINDOWED_NSNOTIFICATION_OBSERVER_H_
+
+#import <Foundation/Foundation.h>
+
+#import "base/mac/scoped_nsobject.h"
+
+namespace base {
+class RunLoop;
+}
+
+// Like WindowedNotificationObserver in content/public/test/test_utils.h, this
+// starts watching for a notification upon construction and can wait until the
+// notification is observed. This guarantees that a notification fired between
+// calls to init and wait will be caught.
+@interface WindowedNSNotificationObserver : NSObject {
+ @private
+  base::scoped_nsobject<NSString> bundleId_;
+  BOOL notificationReceived_;
+  base::RunLoop* runLoop_;
+}
+
+// Watch for an NSNotification on the default notification center.
+- (id)initForNotification:(NSString*)name;
+
+// Watch for an NSNotification on the shared workspace notification center for
+// the
+// given application.
+- (id)initForWorkspaceNotification:(NSString*)name bundleId:(NSString*)bundleId;
+
+// Returns if the notification has been observed, or spins a RunLoop until it
+// is. Stops observing.
+- (void)wait;
+@end
+
+#endif  // UI_BASE_TEST_WINDOWED_NSNOTIFICATION_OBSERVER_H_