Revert "Add support for Increase Contrast on iOS (flutter#15343)"

This reverts commit 0886205.

Author: NoamDev

lib/ui/window.dart

@@ -1212,7 +1212,6 @@ class AccessibilityFeatures {
   static const int _kDisableAnimationsIndex = 1 << 2;
   static const int _kBoldTextIndex = 1 << 3;
   static const int _kReduceMotionIndex = 1 << 4;
-  static const int _kHighContrastIndex = 1 << 5;
 
   // A bitfield which represents each enabled feature.
   final int _index;
@@ -1240,11 +1239,6 @@ class AccessibilityFeatures {
   /// Only supported on iOS.
   bool get reduceMotion => _kReduceMotionIndex & _index != 0;
 
-  /// The platform is requesting that UI be rendered with darker colors.
-  ///
-  /// Only supported on iOS.
-  bool get highContrast => _kHighContrastIndex & _index != 0;
-
   @override
   String toString() {
     final List<String> features = <String>[];
@@ -1258,8 +1252,6 @@ class AccessibilityFeatures {
       features.add('boldText');
     if (reduceMotion)
       features.add('reduceMotion');
-    if (highContrast)
-      features.add('highContrast');
     return 'AccessibilityFeatures$features';
   }
 

lib/ui/window/window.h

@@ -44,7 +44,6 @@ enum class AccessibilityFeatureFlag : int32_t {
   kDisableAnimations = 1 << 2,
   kBoldText = 1 << 3,
   kReduceMotion = 1 << 4,
-  kHighContrast = 1 << 5,
 };
 
 class WindowClient {

lib/web_ui/lib/src/ui/window.dart

@@ -996,7 +996,6 @@ class AccessibilityFeatures {
   static const int _kDisableAnimationsIndex = 1 << 2;
   static const int _kBoldTextIndex = 1 << 3;
   static const int _kReduceMotionIndex = 1 << 4;
-  static const int _kHighContrastIndex = 1 << 5;
 
   // A bitfield which represents each enabled feature.
   final int _index;
@@ -1024,11 +1023,6 @@ class AccessibilityFeatures {
   /// Only supported on iOS.
   bool get reduceMotion => _kReduceMotionIndex & _index != 0;
 
-  /// The platform is requesting that UI be rendered with darker colors.
-  ///
-  /// Only supported on iOS.
-  bool get highContrast => _kHighContrastIndex & _index != 0;
-
   @override
   String toString() {
     final List<String> features = <String>[];
@@ -1047,9 +1041,6 @@ class AccessibilityFeatures {
     if (reduceMotion) {
       features.add('reduceMotion');
     }
-    if (highContrast) {
-      features.add('highContrast');
-    }
     return 'AccessibilityFeatures$features';
   }
 

shell/platform/darwin/ios/framework/Source/FlutterViewController.mm

@@ -298,11 +298,6 @@ - (void)setupNotificationCenterObservers {
                  name:UIAccessibilityBoldTextStatusDidChangeNotification
                object:nil];
 
-  [center addObserver:self
-             selector:@selector(onAccessibilityStatusChanged:)
-                 name:UIAccessibilityDarkerSystemColorsStatusDidChangeNotification
-               object:nil];
-
   [center addObserver:self
              selector:@selector(onUserSettingsChanged:)
                  name:UIContentSizeCategoryDidChangeNotification
@@ -967,8 +962,6 @@ - (void)onAccessibilityStatusChanged:(NSNotification*)notification {
     flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kReduceMotion);
   if (UIAccessibilityIsBoldTextEnabled())
     flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kBoldText);
-  if (UIAccessibilityDarkerSystemColorsEnabled())
-    flags |= static_cast<int32_t>(flutter::AccessibilityFeatureFlag::kHighContrast);
 #if TARGET_OS_SIMULATOR
   // There doesn't appear to be any way to determine whether the accessibility
   // inspector is enabled on the simulator. We conservatively always turn on the