Fix for voice-over accessibility issue with tab switcher.

ios/chrome/browser/ui/tab_switcher/tab_switcher_panel_cell.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_panel_cell.h"
 
 #include "base/mac/scoped_nsobject.h"
 #import "ios/chrome/browser/tabs/tab.h"
 #import "ios/chrome/browser/ui/fade_truncated_label.h"
 #import "ios/chrome/browser/ui/image_util.h"
@@ skipping 13 matching lines @@
 namespace gfx {
 class ImageSkia;
 }
 
 namespace {
 const CGFloat kFontSize = 16;
 const CGFloat kCellCornerRadius = 2;
 const CGFloat kBarHeight = 44;
 const CGFloat kTitleLabelTextAlpha = .54;
 const CGFloat kNewTabIconAlpha = .87;
-}  // Anonymous namespace
+}
 
 CGFloat tabSwitcherLocalSessionCellTopBarHeight() {
   return kBarHeight;
 }
 
 @interface TabSwitcherSessionCell ()
 
 // Returns the container view with rounded corners to which all cell subviews
 // should be added.
 - (UIView*)containerView;
 
 @end
 
 @implementation TabSwitcherSessionCell {
   base::scoped_nsobject<UIView> _containerView;
   CGSize _cachedShadowSize;
 }
 
+@synthesize delegate = _delegate;
+
 // Returns the cell's identifier used for the cell's re-use.
 + (NSString*)identifier {
   return NSStringFromClass([self class]);
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     [self contentView].isAccessibilityElement = YES;
     _containerView.reset([[UIView alloc] initWithFrame:self.bounds]);
@@ skipping 36 matching lines @@
 
 @implementation TabSwitcherLocalSessionCell {
   base::scoped_nsobject<UIView> _topBar;
   base::scoped_nsobject<UILabel> _titleLabel;
   base::scoped_nsobject<UIImageView> _favicon;
   base::scoped_nsobject<UIButton> _closeButton;
   base::scoped_nsobject<UIImageView> _shadow;
   base::scoped_nsobject<UIImageView> _snapshot;
   base::scoped_nsobject<TabSwitcherButton> _snapshotButton;
   PendingSnapshotRequest _currentPendingSnapshotRequest;
-  id<SessionCellDelegate> _delegate;  // weak
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     // Top bar.
     _topBar.reset([[UIView alloc] initWithFrame:CGRectZero]);
     [_topBar setTranslatesAutoresizingMaskIntoConstraints:NO];
     [[self containerView] addSubview:_topBar];
 
@@ skipping 135 matching lines @@
     textColor = [[MDCPalette greyPalette] tint700];
     snapshotBackgroundColor = [UIColor whiteColor];
   }
   [_topBar setBackgroundColor:topBarBackgroundColor];
   [[_closeButton imageView] setTintColor:closeButtonTintColor];
   [_titleLabel setTextColor:textColor];
   [_titleLabel setBackgroundColor:topBarBackgroundColor];
   [_snapshot setBackgroundColor:snapshotBackgroundColor];
 }
 
-- (void)setDelegate:(id<SessionCellDelegate>)delegate {
-  _delegate = delegate;
-}
-
 - (void)snapshotPressed {
-  [_delegate cellPressed:self];
+  [self.delegate cellPressed:self];
 }
 
 - (void)closeButtonPressed {
-  [_delegate deleteButtonPressedForCell:self];
+  [self.delegate deleteButtonPressedForCell:self];
 }
 
 - (void)prepareForReuse {
   [[self cache] cancelPendingSnapshotRequest:_currentPendingSnapshotRequest];
   _currentPendingSnapshotRequest.clear();
   [_snapshot setImage:nil];
   [_snapshotButton resetState];
   [super prepareForReuse];
 }
 
 - (TabSwitcherCache*)cache {
-  return [_delegate tabSwitcherCache];
+  return [self.delegate tabSwitcherCache];
 }
 
 #pragma mark - UIAccessibilityAction
 
 - (NSArray*)accessibilityCustomActions {
   base::scoped_nsobject<NSMutableArray> customActions(
       [[NSMutableArray alloc] init]);
   base::scoped_nsobject<UIAccessibilityCustomAction> customAction(
       [[UIAccessibilityCustomAction alloc]
           initWithName:l10n_util::GetNSString(IDS_IOS_TAB_SWITCHER_CLOSE_TAB)
                 target:self
               selector:@selector(closeButtonPressed)]);
   [customActions addObject:customAction.autorelease()];
   return customActions.autorelease();
 }
 
 @end
 
 @implementation TabSwitcherDistantSessionCell {
   base::scoped_nsobject<UILabel> _titleLabel;
   base::scoped_nsobject<UIImageView> _favicon;
   base::scoped_nsobject<UIImageView> _newTabIcon;
   base::scoped_nsobject<UIView> _verticallyCenteredView;
   base::scoped_nsobject<TabSwitcherButton> _raisedButton;
   base::scoped_nsobject<NSOperation> _faviconObtainer;
-  id<SessionCellDelegate> _delegate;  // weak
 }
 
 - (instancetype)initWithFrame:(CGRect)frame {
   self = [super initWithFrame:frame];
   if (self) {
     // Create and add the button that contains all other subviews.
     _raisedButton.reset([[TabSwitcherButton alloc] initWithFrame:CGRectZero]);
     [_raisedButton setTranslatesAutoresizingMaskIntoConstraints:NO];
     [_raisedButton addTarget:self
                       action:@selector(cellPressed)
@@ skipping 100 matching lines @@
                      }];
   };
   GURL gurlCopy = gurl;
   _faviconObtainer.reset([[NSBlockOperation blockOperationWithBlock:^{
     TabSwitcherGetFavicon(gurlCopy, browserState, block);
   }] retain]);
   NSOperationQueue* operationQueue = [NSOperationQueue mainQueue];
   [operationQueue addOperation:_faviconObtainer];
 }
 
-- (void)setDelegate:(id<SessionCellDelegate>)delegate {
-  _delegate = delegate;
-}
-
 - (void)cellPressed {
-  [_delegate cellPressed:self];
+  [self.delegate cellPressed:self];
 }
 
 - (void)prepareForReuse {
   [_newTabIcon setAlpha:0];
   [_faviconObtainer cancel];
   _faviconObtainer.reset();
   [_raisedButton setAlpha:0];
   [_raisedButton resetState];
   [super prepareForReuse];
 }
 
 @end