Remove trailing button from voiceover when it's disabled.

This prevents the trialing button from being accessible by
voiceover when it's not enabled.

Bug: 985763
Change-Id: Ibf1e1270984c76df5c54373beb15f0f222b6ab07
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1713513
Commit-Queue: Stepan Khapugin <stkhapugin@chromium.org>
Commit-Queue: Robbie Gibson <rkgibson@google.com>
Auto-Submit: Stepan Khapugin <stkhapugin@chromium.org>
Reviewed-by: Robbie Gibson <rkgibson@google.com>
Cr-Commit-Position: refs/heads/master@{#679951}

ios/chrome/browser/ui/location_bar/location_bar_steady_view.h

@@ -44,6 +44,10 @@
 // |display| is NO. Will animate change if |animated| is YES.
 - (void)displayBadge:(BOOL)display animated:(BOOL)animated;
 
+// Toggles |enabled| state of the trailing button and updates accessibility
+// appropriately.
+- (void)enableTrailingButton:(BOOL)enabled;
+
 // The tappable button representing the location bar.
 @property(nonatomic, strong) UIButton* locationButton;
 // The label displaying the current location URL.

ios/chrome/browser/ui/location_bar/location_bar_steady_view.mm

@@ -334,6 +334,11 @@ const CGFloat kButtonTrailingSpacing = 10;
   [self.leadingButton displayBadge:display animated:animated];
 }
 
+- (void)enableTrailingButton:(BOOL)enabled {
+  self.trailingButton.enabled = enabled;
+  [self updateAccessibility];
+}
+
 #pragma mark - UIResponder
 
 // This is needed for UIMenu
@@ -380,6 +385,12 @@ const CGFloat kButtonTrailingSpacing = 10;
     self.locationButton.accessibilityValue =
         [NSString stringWithFormat:@"%@", self.locationLabel.text];
   }
+
+  if (self.trailingButton.enabled) {
+    [self.accessibleElements addObject:self.trailingButton];
+  } else {
+    [self.accessibleElements removeObject:self.trailingButton];
+  }
 }
 
 // Returns the font size for the location label.

ios/chrome/browser/ui/location_bar/location_bar_view_controller.mm

@@ -255,7 +255,7 @@ typedef NS_ENUM(int, TrailingButtonState) {
 - (void)setShareButtonEnabled:(BOOL)enabled {
   _shareButtonEnabled = enabled;
   if (self.trailingButtonState == kShareButton) {
-    self.locationBarSteadyView.trailingButton.enabled = enabled;
+    [self.locationBarSteadyView enableTrailingButton:enabled];
   }
 }
 
@@ -399,8 +399,7 @@ typedef NS_ENUM(int, TrailingButtonState) {
           forState:UIControlStateNormal];
       self.locationBarSteadyView.trailingButton.accessibilityLabel =
           l10n_util::GetNSString(IDS_IOS_TOOLS_MENU_SHARE);
-      self.locationBarSteadyView.trailingButton.enabled =
-          self.shareButtonEnabled;
+      [self.locationBarSteadyView enableTrailingButton:self.shareButtonEnabled];
       break;
     };
     case kVoiceSearchButton: {
@@ -419,7 +418,7 @@ typedef NS_ENUM(int, TrailingButtonState) {
           forState:UIControlStateNormal];
       self.locationBarSteadyView.trailingButton.accessibilityLabel =
           l10n_util::GetNSString(IDS_IOS_TOOLS_MENU_VOICE_SEARCH);
-      self.locationBarSteadyView.trailingButton.enabled = YES;
+      [self.locationBarSteadyView enableTrailingButton:YES];
     }
   }
 }