Upstream ios/web/web_state/ui support classes

ios/web/web_state/ui/crw_touch_tracking_recognizer.h

+// Copyright 2012 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_WEB_WEB_STATE_UI_CRW_TOUCH_TRACKING_RECOGNIZER_H_
+#define IOS_WEB_WEB_STATE_UI_CRW_TOUCH_TRACKING_RECOGNIZER_H_
+
+#import <UIKit/UIGestureRecognizerSubclass.h>
+
+// Methods implemented by the delegate of the CRWTouchTrackingRecognizer.
+@protocol CRWTouchTrackingDelegate
+
+// Called with YES when touches began, with NO when touches are ended or
+// cancelled.
+- (void)touched:(BOOL)touched;
+
+@end
+
+// UIGestureRecognizer subclass that informs delegate about touches using
+// simplified interface.
+@interface CRWTouchTrackingRecognizer : UIGestureRecognizer
+
+// CRWTouchTrackingRecognizer delegate.
+@property(nonatomic, assign) id<CRWTouchTrackingDelegate> touchTrackingDelegate;
+
+// Designated initializer for CRWTouchTrackingRecognizer.
+- (id)initWithDelegate:(id<CRWTouchTrackingDelegate>)delegate;
+
+@end
+
+#endif  // IOS_WEB_WEB_STATE_UI_CRW_TOUCH_TRACKING_RECOGNIZER_H_