Fix menu list and list box screen reader accessibility.

content/browser/accessibility/browser_accessibility_manager_mac.mm

 // Copyright (c) 2012 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.
 
 #include "content/browser/accessibility/browser_accessibility_manager_mac.h"
 
 #import "base/logging.h"
 #import "content/browser/accessibility/browser_accessibility_cocoa.h"
 #import "content/browser/accessibility/browser_accessibility_mac.h"
 #include "content/common/accessibility_messages.h"
@@ skipping 26 matching lines @@
   empty_document.role = ui::AX_ROLE_ROOT_WEB_AREA;
   empty_document.state =
       1 << ui::AX_STATE_READ_ONLY;
   ui::AXTreeUpdate update;
   update.nodes.push_back(empty_document);
   return update;
 }
 
 BrowserAccessibility* BrowserAccessibilityManagerMac::GetFocus(
     BrowserAccessibility* root) {
-  BrowserAccessibility* node = GetActiveDescendantFocus(root);
-  return node;
+  // On Mac, list boxes should always get focus on the whole list, otherwise
+  // information about the number of selected items will never be reported.
+  BrowserAccessibility* node = BrowserAccessibilityManager::GetFocus(root);
+  if (node && node->GetRole() == ui::AX_ROLE_LIST_BOX)
+    return node;
+
+  // For other roles, follow the active descendant.
+  return GetActiveDescendantFocus(root);
 }
 
 void BrowserAccessibilityManagerMac::NotifyAccessibilityEvent(
     ui::AXEvent event_type,
     BrowserAccessibility* node) {
   if (!node->IsNative())
     return;
 
+  if (event_type == ui::AX_EVENT_FOCUS &&
+      node->GetRole() == ui::AX_ROLE_LIST_BOX_OPTION &&
+      node->HasState(ui::AX_STATE_SELECTED) &&
+      node->GetParent() &&
+      node->GetParent()->GetRole() == ui::AX_ROLE_LIST_BOX) {
+    node = node->GetParent();
+    SetFocus(node, false);
+  }
+
   // Refer to AXObjectCache.mm (webkit).
   NSString* event_id = @"";
   switch (event_type) {
     case ui::AX_EVENT_ACTIVEDESCENDANTCHANGED:
       if (node->GetRole() == ui::AX_ROLE_TREE) {
         event_id = NSAccessibilitySelectedRowsChangedNotification;
       } else {
         event_id = NSAccessibilityFocusedUIElementChangedNotification;
         BrowserAccessibility* active_descendant_focus =
             GetActiveDescendantFocus(GetRoot());
@@ skipping 65 matching lines @@
     case ui::AX_EVENT_MENU_LIST_ITEM_SELECTED:
       // Not used on Mac.
       return;
     case ui::AX_EVENT_TEXT_CHANGED:
       // Not used on Mac.
       return;
     default:
       LOG(WARNING) << "Unknown accessibility event: " << event_type;
       return;
   }
+
   BrowserAccessibilityCocoa* native_node = node->ToBrowserAccessibilityCocoa();
   DCHECK(native_node);
   NSAccessibilityPostNotification(native_node, event_id);
 }
 
 void BrowserAccessibilityManagerMac::OnAtomicUpdateFinished(
     bool root_changed, const std::vector<ui::AXTreeDelegate::Change>& changes) {
   BrowserAccessibilityManager::OnAtomicUpdateFinished(root_changed, changes);
 
   bool created_live_region = false;
@@ skipping 15 matching lines @@
   // page for live regions once. By recreating the NSAccessibility
   // object for the root of the tree, we force VoiceOver to clear out its
   // internal state and find newly-added live regions this time.
   BrowserAccessibilityMac* root =
       static_cast<BrowserAccessibilityMac*>(GetRoot());
   root->RecreateNativeObject();
   NotifyAccessibilityEvent(ui::AX_EVENT_CHILDREN_CHANGED, root);
 }
 
 }  // namespace content