[ObjC ARC] Converts ios/chrome/browser/ui/stack_view:stack_view to ARC.

ios/chrome/browser/ui/stack_view/stack_view_controller_private.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 IOS_CHROME_BROWSER_UI_STACK_VIEW_STACK_VIEW_CONTROLLER_PRIVATE_H_
 #define IOS_CHROME_BROWSER_UI_STACK_VIEW_STACK_VIEW_CONTROLLER_PRIVATE_H_
 
 #import "ios/chrome/browser/ui/stack_view/card_set.h"
 #import "ios/chrome/browser/ui/stack_view/stack_view_controller.h"
 
@@ skipping 50 matching lines @@
 // Makes |cardSet| the active set, updating the UI accordingly.
 - (void)setActiveCardSet:(CardSet*)cardSet;
 
 // Returns YES if both decks should be visible.
 - (BOOL)bothDecksShouldBeDisplayed;
 
 // Returns the region, in scroll view coordinates, of the inactive deck.
 - (CGRect)inactiveDeckRegion;
 
 // The currently active card set.
-@property(nonatomic, readonly) CardSet* activeCardSet;
+@property(nonatomic, weak, readonly) CardSet* activeCardSet;
 
 // The current transition style.
 @property(nonatomic, assign) StackTransitionStyle transitionStyle;
 
 // Will be set to YES when a transition animation is cancelled before it can
 // finish.
 @property(nonatomic, assign) BOOL transitionWasCancelled;
 
 // The owner of |transitionToolbarController|.
-@property(nonatomic, retain) id<ToolbarOwner> transitionToolbarOwner;
+@property(nonatomic, strong) id<ToolbarOwner> transitionToolbarOwner;
 
 // The toolbar controller used in transition animations.
-@property(nonatomic, retain) ToolbarController* transitionToolbarController;
+@property(nonatomic, strong) ToolbarController* transitionToolbarController;
 
 // The dummy view used in the transition animation.
-@property(nonatomic, retain) UIView* dummyToolbarBackgroundView;
+@property(nonatomic, strong) UIView* dummyToolbarBackgroundView;
 
 // The cached frame of the transition toolbar's frame.
 @property(nonatomic, assign) CGRect transitionToolbarFrame;
 
 // Records which card was tapped mid-presentation animation, if any.
 // TODO(crbug.com/546209): Implement reversed animations for dismissing with a
 // new selected card mid-presentation.
-@property(nonatomic, retain) StackCard* transitionTappedCard;
+@property(nonatomic, strong) StackCard* transitionTappedCard;
 
 // |YES| if there is card set animation being processed.
 @property(nonatomic, readonly) BOOL inActiveDeckChangeAnimation;
 
 @end
 
 @interface StackViewController (Testing)
 
 // The driver of scroll events.
 @property(nonatomic, readonly) UIScrollView* scrollView;
 
 @end
 
 #endif  // IOS_CHROME_BROWSER_UI_STACK_VIEW_STACK_VIEW_CONTROLLER_PRIVATE_H_