[ios] Fix settings switch accessibility value and hint

ios/chrome/browser/ui/settings/cells/sync_switch_item.mm

 // Copyright 2016 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/settings/cells/sync_switch_item.h"
 
 #import "ios/chrome/browser/ui/colors/MDCPalette+CrAdditions.h"
+#include "ios/chrome/grit/ios_strings.h"
 #import "ios/third_party/material_components_ios/src/components/Palettes/src/MaterialPalettes.h"
 #import "ios/third_party/material_roboto_font_loader_ios/src/src/MaterialRobotoFontLoader.h"
+#include "ui/base/l10n/l10n_util_mac.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 // Padding used on the leading and trailing edges of the cell.
 const CGFloat kHorizontalPadding = 16;
 
 // Padding used on the top and bottom edges of the cell.
@@ skipping 11 matching lines @@
 @synthesize detailText = _detailText;
 @synthesize on = _on;
 @synthesize enabled = _enabled;
 @synthesize dataType = _dataType;
 
 - (instancetype)initWithType:(NSInteger)type {
   self = [super initWithType:type];
   if (self) {
     self.cellClass = [SyncSwitchCell class];
     self.enabled = YES;
-    self.accessibilityTraits |= UIAccessibilityTraitButton;
   }
   return self;
 }
 
 - (void)configureCell:(SyncSwitchCell*)cell {
   [super configureCell:cell];
   cell.textLabel.text = self.text;
   cell.detailTextLabel.text = self.detailText;
   cell.switchView.enabled = self.isEnabled;
   cell.switchView.on = self.isOn;
@@ skipping 37 matching lines @@
     [self.contentView addSubview:_detailTextLabel];
 
     _detailTextLabel.font =
         [[MDFRobotoFontLoader sharedInstance] mediumFontOfSize:14];
     _detailTextLabel.textColor = [[MDCPalette greyPalette] tint500];
     _detailTextLabel.numberOfLines = 0;
 
     _switchView = [[UISwitch alloc] initWithFrame:CGRectZero];
     _switchView.translatesAutoresizingMaskIntoConstraints = NO;
     _switchView.onTintColor = [[MDCPalette cr_bluePalette] tint500];
+    _switchView.accessibilityHint = l10n_util::GetNSString(
+        IDS_IOS_TOGGLE_SETTING_SWITCH_ACCESSIBILITY_HINT);
     [self.contentView addSubview:_switchView];
 
     [self setConstraints];
   }
 
   return self;
 }
 
 - (void)setConstraints {
   UIView* contentView = self.contentView;
@@ skipping 63 matching lines @@
 
 - (CGPoint)accessibilityActivationPoint {
   // Center the activation point over the switch, so that double-tapping toggles
   // the switch.
   CGRect switchFrame =
       UIAccessibilityConvertFrameToScreenCoordinates(_switchView.frame, self);
   return CGPointMake(CGRectGetMidX(switchFrame), CGRectGetMidY(switchFrame));
 }
 
 - (NSString*)accessibilityHint {
-  return _switchView.accessibilityHint;
+  if (_switchView.isEnabled) {
+    return _switchView.accessibilityHint;

[edchin, 2017/01/12 22:13:45]

Should both the row and the switch have the same hint? 

[sczs, 2017/01/12 22:26:17]

Yes, we are aiming to imitate iOS settings switches. In this case only the row
is an accessible element, so only one hint is read.

[edchin, 2017/01/12 22:37:54]

Why not set the hint only on the row if it is the only accessible element?

[lpromero, 2017/01/13 10:01:33]

No action needed: If in the future we need to have a secondary element within
the cell, the row will stop being an accessibility element and will list its
children as elements. Sergio's approach seems more maintainable this way, where
the switch holds the info no matter what, and the row makes the connection,
based on the behavior it decides it wants.

+  } else {
+    return @"";
+  }
 }
 
 - (NSString*)accessibilityLabel {
   if (_detailTextLabel.text) {
     return [NSString
         stringWithFormat:@"%@, %@", _textLabel.text, _detailTextLabel.text];
   }
   return _textLabel.text;
 }
 
 - (NSString*)accessibilityValue {
-  return _switchView.accessibilityValue;
+  if (_switchView.on) {
+    return l10n_util::GetNSString(IDS_IOS_SETTING_ON);
+  } else {
+    return l10n_util::GetNSString(IDS_IOS_SETTING_OFF);
+  }
 }
 
 @end