Add importantForAccessibility to AccessibilityProps and wire with FormsStakingContext

Summary:
Changelog:
[iOS][Added] - Add `importantForAccessibility` to `AccessibilityProps`

Reviewed By: shergin

Differential Revision: D22490327

fbshipit-source-id: aec7ff64ea6ddfe29bad085b87d09906fa8ee029

ReactCommon/fabric/components/view/ViewShadowNode.cpp

@@ -48,7 +48,8 @@ void ViewShadowNode::initialize() noexcept {
        viewProps.yogaStyle.positionType() == YGPositionTypeAbsolute) ||
       viewProps.yogaStyle.display() == YGDisplayNone ||
       viewProps.getClipsContentToBounds() ||
-      isColorMeaningful(viewProps.shadowColor);
+      isColorMeaningful(viewProps.shadowColor) ||
+      viewProps.importantForAccessibility != ImportantForAccessibility::Auto;
 
   bool formsView = isColorMeaningful(viewProps.backgroundColor) ||
       isColorMeaningful(viewProps.foregroundColor) ||

ReactCommon/fabric/components/view/accessibility/AccessibilityPrimitives.h

@@ -61,5 +61,12 @@ constexpr bool operator!=(
   return !(rhs == lhs);
 }
 
+enum class ImportantForAccessibility {
+  Auto,
+  Yes,
+  No,
+  NoHideDescendants,
+};
+
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/view/accessibility/AccessibilityProps.cpp

@@ -83,6 +83,11 @@ AccessibilityProps::AccessibilityProps(
           "onAccessibilityAction",
           sourceProps.onAccessibilityAction,
           {})),
+      importantForAccessibility(convertRawProp(
+          rawProps,
+          "importantForAccessibility",
+          sourceProps.importantForAccessibility,
+          ImportantForAccessibility::Auto)),
       testId(convertRawProp(rawProps, "testId", sourceProps.testId, "")) {}
 
 #pragma mark - DebugStringConvertible

ReactCommon/fabric/components/view/accessibility/AccessibilityProps.h

@@ -37,6 +37,8 @@ class AccessibilityProps {
   bool onAccessibilityMagicTap{};
   bool onAccessibilityEscape{};
   bool onAccessibilityAction{};
+  ImportantForAccessibility importantForAccessibility{
+      ImportantForAccessibility::Auto};
   std::string testId{""};
 
 #pragma mark - DebugStringConvertible

ReactCommon/fabric/components/view/accessibility/accessibilityPropsConversions.h

@@ -122,5 +122,42 @@ inline void fromRawValue(const RawValue &value, AccessibilityState &result) {
   }
 }
 
+inline std::string toString(
+    const ImportantForAccessibility &importantForAccessibility) {
+  switch (importantForAccessibility) {
+    case ImportantForAccessibility::Auto:
+      return "auto";
+    case ImportantForAccessibility::Yes:
+      return "yes";
+    case ImportantForAccessibility::No:
+      return "no";
+    case ImportantForAccessibility::NoHideDescendants:
+      return "no-hide-descendants";
+  }
+}
+
+inline void fromRawValue(
+    const RawValue &value,
+    ImportantForAccessibility &result) {
+  auto string = (std::string)value;
+  if (string == "auto") {
+    result = ImportantForAccessibility::Auto;
+    return;
+  }
+  if (string == "yes") {
+    result = ImportantForAccessibility::Yes;
+    return;
+  }
+  if (string == "no") {
+    result = ImportantForAccessibility::No;
+    return;
+  }
+  if (string == "no-hide-descendants") {
+    result = ImportantForAccessibility::NoHideDescendants;
+    return;
+  }
+  abort();
+}
+
 } // namespace react
 } // namespace facebook