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

ios/chrome/browser/ui/tab_switcher/tab_switcher_view.mm

 // 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.
 
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_view.h"
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
-#include "base/mac/scoped_nsobject.h"
 #include "base/metrics/user_metrics.h"
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
 #include "ios/chrome/browser/ui/rtl_geometry.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_header_view.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_controller.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_overlay_view.h"
 #import "ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_view.h"
 #include "ios/chrome/grit/ios_strings.h"
 #import "ios/third_party/material_components_ios/src/components/Buttons/src/MaterialButtons.h"
 #import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
 #include "ui/base/l10n/l10n_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 const CGFloat kHeaderHeight = 95;
 const CGFloat kNewTabButtonMarginFromEdges = 48;
 const CGFloat kNewTabButtonWidth = 48;
 }
 
 @interface TabSwitcherView ()<UIScrollViewDelegate> {
-  base::scoped_nsobject<TabSwitcherHeaderView> _headerView;
-  base::scoped_nsobject<UIScrollView> _scrollView;
-  base::scoped_nsobject<MDCButton> _openNewTabButton;
-  base::scoped_nsobject<NSMutableArray> _panels;
+  TabSwitcherHeaderView* _headerView;
+  UIScrollView* _scrollView;
+  MDCButton* _openNewTabButton;
+  NSMutableArray* _panels;
   ios_internal::NewTabButtonStyle _openNewTabButtonStyle;
   NSInteger _previousPanelIndex;
 }
 
 // Returns the header view frame.
 - (CGRect)headerViewFrame;
 // Returns the scrollview frame.
 - (CGRect)scrollViewFrame;
 // Returns the new tab button frame.
 - (CGRect)openNewTabButtonFrame;
@@ skipping 11 matching lines @@
 
 @implementation TabSwitcherView
 
 @synthesize delegate = delegate_;
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     _openNewTabButtonStyle = ios_internal::NewTabButtonStyle::UNINITIALIZED;
     [self loadSubviews];
-    _panels.reset([[NSMutableArray alloc] init]);
+    _panels = [[NSMutableArray alloc] init];
     _previousPanelIndex = -1;
   }
   return self;
 }
 
 - (TabSwitcherHeaderView*)headerView {
   return _headerView;
 }
 
 - (UIScrollView*)scrollView {
@@ skipping 22 matching lines @@
   [_scrollView addSubview:view];
   [_panels insertObject:view atIndex:index];
   [self updateScrollViewContent];
 }
 
 - (void)removePanelViewAtIndex:(NSUInteger)index {
   [self removePanelViewAtIndex:index updateScrollView:YES];
 }
 
 - (void)removePanelViewAtIndex:(NSUInteger)index updateScrollView:(BOOL)update {
-  DCHECK_EQ([[_panels objectAtIndex:index] superview], _scrollView.get());
+  DCHECK_EQ([[_panels objectAtIndex:index] superview], _scrollView);
   [[_panels objectAtIndex:index] removeFromSuperview];
   [_panels removeObjectAtIndex:index];
   if (update)
     [self updateScrollViewContent];
 }
 
 - (NSInteger)currentPanelIndex {
   return [self currentPageIndex];
 }
 
@@ skipping 46 matching lines @@
   currentContentSize.width = [_panels count] * panelSize.width;
   [_scrollView setContentSize:currentContentSize];
   for (NSUInteger i = 0; i < [_panels count]; i++) {
     id panelView = [_panels objectAtIndex:i];
     [panelView setFrame:[self frameForPanelAtIndex:i]];
   }
 }
 
 - (void)loadSubviews {
   // Creates and add the header view showing the list of panels.
-  base::scoped_nsobject<TabSwitcherHeaderView> headerView(
-      [[TabSwitcherHeaderView alloc] initWithFrame:[self headerViewFrame]]);
+  TabSwitcherHeaderView* headerView =
+      [[TabSwitcherHeaderView alloc] initWithFrame:[self headerViewFrame]];
   [self addSubview:headerView];
   _headerView = headerView;
 
   // Creates and add the scrollview containing the panels.
-  base::scoped_nsobject<UIScrollView> scrollView(
-      [[UIScrollView alloc] initWithFrame:[self scrollViewFrame]]);
+  UIScrollView* scrollView =
+      [[UIScrollView alloc] initWithFrame:[self scrollViewFrame]];
   [scrollView setBackgroundColor:[[MDCPalette greyPalette] tint900]];
   [scrollView setAlwaysBounceHorizontal:YES];
   [scrollView setDelegate:self];
   [scrollView setPagingEnabled:YES];
   [scrollView setDelegate:self];
   if (UseRTLLayout())
     [scrollView setTransform:CGAffineTransformMakeScale(-1, 1)];
   [self addSubview:scrollView];
   _scrollView = scrollView;
 
   // Creates and add the floating new tab button.
-  _openNewTabButton.reset([[MDCFloatingButton alloc] init]);
+  _openNewTabButton = [[MDCFloatingButton alloc] init];
   UIImage* openNewTabButtonImage =
       [[UIImage imageNamed:@"tabswitcher_new_tab_fab"]
           imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
   [_openNewTabButton setImage:openNewTabButtonImage
                      forState:UIControlStateNormal];
   [[_openNewTabButton imageView] setTintColor:[UIColor whiteColor]];
   [_openNewTabButton setFrame:[self openNewTabButtonFrame]];
   // When the button is positioned with autolayout, the animation of the
   // button's position conflicts with other animations.
   [_openNewTabButton
@@ skipping 155 matching lines @@
     case ios_internal::GRAY:
       [self.delegate openNewTabInPanelAtIndex:panelIndex];
       return YES;
     case ios_internal::UNINITIALIZED:
     case ios_internal::HIDDEN:
       return NO;
   }
 }
 
 @end