MacViews: Fix accessibility hit tests, provide AXTitle

ui/accessibility/platform/ax_platform_node_mac.mm

 // Copyright 2014 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 "ui/accessibility/platform/ax_platform_node_mac.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/strings/sys_string_conversions.h"
 #import "ui/accessibility/ax_node_data.h"
@@ skipping 226 matching lines @@
 - (NSString*)AXRole {
   if (!node_)
     return nil;
   return [[self class] nativeRoleFromAXRole:node_->GetData().role];
 }
 
 - (NSValue*)AXSize {
   return [NSValue valueWithSize:self.boundsInScreen.size];
 }
 
+- (NSString*)AXTitle {
+  std::string value;
+  if (node_->GetStringAttribute(ui::AX_ATTR_NAME, &value))
+    return base::SysUTF8ToNSString(value);
+  return nil;
+}
+
 // NSAccessibility informal protocol implementation.
 
 - (BOOL)accessibilityIsIgnored {
   return [[self AXRole] isEqualToString:NSAccessibilityUnknownRole];
 }
 
 - (id)accessibilityHitTest:(NSPoint)point {
   for (AXPlatformNodeCocoa* child in [self AXChildren]) {
     if (NSPointInRect(point, child.boundsInScreen))
       return [child accessibilityHitTest:point];
   }
   return NSAccessibilityUnignoredAncestor(self);
 }
 
 - (NSArray*)accessibilityActionNames {
   return nil;
 }
 
 - (NSArray*)accessibilityAttributeNames {
+  // These attributes are required on all accessibility objects.
   return @[
     NSAccessibilityChildrenAttribute,
     NSAccessibilityParentAttribute,
     NSAccessibilityPositionAttribute,
     NSAccessibilityRoleAttribute,
     NSAccessibilitySizeAttribute,
+
+    // Title is required for most elements. Cocoa asks for the value even if it
+    // is omitted here, but won't present it to accessibility APIs without this.
+    NSAccessibilityTitleAttribute,
   ];
+  // TODO(tapted): Add additional attributes based on role.
 }
 
 - (BOOL)accessibilityIsAttributeSettable:(NSString*)attribute {
   return NO;
 }
 
 - (id)accessibilityAttributeValue:(NSString*)attribute {
   SEL selector = NSSelectorFromString(attribute);
   if ([self respondsToSelector:selector])
     return [self performSelector:selector];
@@ skipping 33 matching lines @@
 void AXPlatformNodeMac::NotifyAccessibilityEvent(ui::AXEvent event_type) {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
 }
 
 int AXPlatformNodeMac::GetIndexInParent() {
   // TODO(dmazzoni): implement this.  http://crbug.com/396137
   return -1;
 }
 
 }  // namespace ui