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

ios/chrome/browser/ui/stack_view/page_animation_util.mm

 // 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.
 
 #import "ios/chrome/browser/ui/stack_view/page_animation_util.h"
 
 #import <QuartzCore/QuartzCore.h>
 #import <UIKit/UIKit.h>
 
+#import "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/ui/animation_util.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 #import "ios/chrome/browser/ui/stack_view/card_view.h"
 #import "ios/chrome/common/material_timing.h"
 
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
 using ios::material::TimingFunction;
 
 namespace {
 
 const NSTimeInterval kAnimationDuration = 0.25;
 const NSTimeInterval kAnimationHesitation = 0.2;
 
 // Constants used for rotating/translating in in transition-in animations and
 // rotating/translating out in transition-out animations.
 const CGFloat kDefaultRotation = 0.2094;  // 12 degrees.
@@ skipping 23 matching lines @@
 @end
 
 @implementation PaperView
 
 - (id)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     const UIEdgeInsets kShadowStretchInsets = {28.0, 28.0, 28.0, 28.0};
     const UIEdgeInsets kShadowLayoutOutset = {-10.0, -11.0, -12.0, -11.0};
     CGRect shadowFrame = UIEdgeInsetsInsetRect(frame, kShadowLayoutOutset);
-    UIImageView* frameShadowImageView =
-        [[UIImageView alloc] initWithFrame:shadowFrame];
+    base::scoped_nsobject<UIImageView> frameShadowImageView(
+        [[UIImageView alloc] initWithFrame:shadowFrame]);
     [frameShadowImageView
         setAutoresizingMask:(UIViewAutoresizingFlexibleWidth |
                              UIViewAutoresizingFlexibleHeight)];
     [self addSubview:frameShadowImageView];
 
     UIImage* image = [UIImage imageNamed:@"popup_background"];
     image = [image resizableImageWithCapInsets:kShadowStretchInsets];
     [frameShadowImageView setImage:image];
   }
   return self;
@@ skipping 25 matching lines @@
                                               BOOL isOffTheRecord,
                                               void (^extraAnimation)(void),
                                               void (^completion)(void)) {
   CGRect endFrame = view.frame;
   UIView* parent = [view superview];
   NSInteger index = [[parent subviews] indexOfObject:view];
 
   // Create paper background.
   CGRect paperFrame = CGRectOffset(endFrame, 0, paperOffset);
   paperFrame.size.height -= paperOffset;
-  PaperView* paper = [[PaperView alloc] initWithFrame:paperFrame];
+  base::scoped_nsobject<PaperView> paper(
+      [[PaperView alloc] initWithFrame:paperFrame]);
   [parent insertSubview:paper belowSubview:view];
   [paper addSubview:view];
   [paper setBackgroundColor:isOffTheRecord
                                 ? [UIColor colorWithWhite:34 / 255 alpha:1]
                                 : [UIColor whiteColor]];
 
   [CATransaction begin];
   [CATransaction setCompletionBlock:^{
 
     // Put view back where it belongs, with its original frame.
@@ skipping 84 matching lines @@
         if (completion)
           completion();
       }];
 }
 
 void AnimateNewBackgroundPageWithCompletion(CardView* currentPageCard,
                                             CGRect displayFrame,
                                             BOOL isPortrait,
                                             void (^completion)(void)) {
   // Create paper background.
-  PaperView* paper = [[PaperView alloc] initWithFrame:CGRectZero];
+  base::scoped_nsobject<PaperView> paper(
+      [[PaperView alloc] initWithFrame:CGRectZero]);
   UIView* parent = [currentPageCard superview];
   [parent insertSubview:paper aboveSubview:currentPageCard];
   CGRect pageBounds = currentPageCard.bounds;
   [paper setCenter:CGPointMake(CGRectGetMidX(pageBounds),
                                CGRectGetMidY(pageBounds))];
   [paper setBackgroundColor:[UIColor whiteColor]];
   [paper setAlpha:0.0];
 
   CGSize pageSize = currentPageCard.bounds.size;
   CGRect paperFrame =
@@ skipping 241 matching lines @@
   return transform;
 }
 
 CGFloat AnimateOutTransformBreadth() {
   return kDefaultShortSideAxisTranslation;
 }
 
 }  // namespace page_animation_util
 
 }  // namespace ios_internal