[AX Mac] prepare NSAccessibilityStyleRangeForIndexParameterizedAttribute

for migration.

Redirect NSAccessibilityStyleRangeForIndexParameterizedAttribute
implementation to accessibilityStyleRangeForIndex method.

Test: `out/.../accessibility_unittests \
   --gtest_filter="*AccessibilityStyleRangeForIndex*"`

Include-Ci-Only-Tests: true
Cq-Include-Trybots: luci.chromium.try:mac-fieldtrial-tester

Bug: 363275809
Change-Id: I83c9297e3afb68e253361e9b6618cad57ec2259e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6115309
Reviewed-by: David Tseng <dtseng@chromium.org>
Reviewed-by: Jayson Adams <shrike@chromium.org>
Commit-Queue: Alexander Surkov <asurkov@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1406484}

ui/accessibility/platform/ax_platform_node_cocoa.mm

@@ -2460,12 +2460,13 @@ const ui::CocoaActionList& GetCocoaActionListForTesting() {
 }
 
 - (id)AXStyleRangeForIndex:(id)parameter {
-  if (![parameter isKindOfClass:[NSNumber class]])
+  NSNumber* indexNumber = base::apple::ObjCCast<NSNumber>(parameter);
+  if (!indexNumber) {
     return nil;
-
-  // TODO(crbug.com/41456329): Implement this for real.
+  }
   return [NSValue
-      valueWithRange:NSMakeRange(0, [self accessibilityNumberOfCharacters])];
+      valueWithRange:[self accessibilityStyleRangeForIndex:[indexNumber
+                                                               intValue]]];
 }
 
 - (id)AXAttributedStringForRange:(id)parameter {
@@ -3362,10 +3363,12 @@ const ui::CocoaActionList& GetCocoaActionListForTesting() {
 }
 
 - (NSRange)accessibilityStyleRangeForIndex:(NSInteger)index {
-  if (!_node)
+  if (![self instanceActive]) {
     return NSMakeRange(0, 0);
+  }
 
-  return [[self AXStyleRangeForIndex:@(index)] rangeValue];
+  // TODO(crbug.com/41456329): Implement this for real.
+  return NSMakeRange(0, [self accessibilityNumberOfCharacters]);
 }
 
 - (NSRange)accessibilityRangeForLine:(NSInteger)line {

ui/accessibility/platform/ax_platform_node_cocoa_unittest.mm

@@ -820,6 +820,19 @@ TEST_P(AXPlatformNodeCocoaTest, AccessibilityStringForRange) {
   EXPECT_TRUE([string isEqualToString:@"hey"]);
 }
 
+// accessibilityStyleRangeForIndex
+TEST_P(AXPlatformNodeCocoaTest, AccessibilityStyleRangeForIndex) {
+  Init(std::string(R"HTML(
+    ++1 kRootWebArea
+    ++++2 kStaticText name="heybullfrog"
+  )HTML"));
+
+  AXPlatformNodeCocoa* text_field = GetCocoaNode(2);
+  NSRange range = [text_field accessibilityStyleRangeForIndex:0];
+  EXPECT_EQ(range.location, 0U);
+  EXPECT_EQ(range.length, 11U);
+}
+
 // Non-header cells should not support accessibilitySortDirection, even if
 // there's a sort direction in the AXNodeData. Their sort order is "unknown".
 TEST_P(AXPlatformNodeCocoaTest, AccessibilitySortDirectionOnCell) {