Fix DumpAccessibilityEvents tests on Mac and improve test coverage

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"
 
 #include "base/bind.h"
 #import "base/mac/mac_util.h"
 #import "base/mac/scoped_nsobject.h"
 #import "base/mac/sdk_forward_declarations.h"
@@ skipping 204 matching lines @@
       } else {
         mac_notification = NSAccessibilitySelectedChildrenChangedNotification;
       }
       break;
     case ui::AX_EVENT_DOCUMENT_SELECTION_CHANGED: {
       mac_notification = NSAccessibilitySelectedTextChangedNotification;
       // WebKit fires a notification both on the focused object and the root.
       BrowserAccessibility* focus = GetFocus();
       if (!focus)
         break;  // Just fire a notification on the root.
-      NSAccessibilityPostNotification(ToBrowserAccessibilityCocoa(focus),
-                                      mac_notification);
 
       if (base::mac::IsAtLeastOS10_11()) {
         // |NSAccessibilityPostNotificationWithUserInfo| should be used on OS X
         // 10.11 or later to notify Voiceover about text selection changes. This
         // API has been present on versions of OS X since 10.7 but doesn't
         // appear to be needed by Voiceover before version 10.11.
         NSDictionary* user_info =
             GetUserInfoForSelectedTextChangedNotification();
 
         BrowserAccessibility* root = GetRoot();
         if (!root)
           return;
 
         NSAccessibilityPostNotificationWithUserInfo(
             ToBrowserAccessibilityCocoa(focus), mac_notification, user_info);
         NSAccessibilityPostNotificationWithUserInfo(
             ToBrowserAccessibilityCocoa(root), mac_notification, user_info);
         return;
+      } else {
+        NSAccessibilityPostNotification(ToBrowserAccessibilityCocoa(focus),
+                                        mac_notification);
       }
       break;
     }
     case ui::AX_EVENT_CHECKED_STATE_CHANGED:
       mac_notification = NSAccessibilityValueChangedNotification;
       break;
     case ui::AX_EVENT_VALUE_CHANGED:
       mac_notification = NSAccessibilityValueChangedNotification;
       if (base::mac::IsAtLeastOS10_11() && text_edits_.size()) {
         // It seems that we don't need to distinguish between deleted and
@@ skipping 26 matching lines @@
           native_node, NSAccessibilityLiveRegionCreatedNotification);
       // Voiceover requires a live region changed notification to actually
       // announce the live region.
       NotifyAccessibilityEvent(BrowserAccessibilityEvent::FromTreeChange,
                                ui::AX_EVENT_LIVE_REGION_CHANGED, node);
       return;
     case ui::AX_EVENT_LIVE_REGION_CHANGED: {
       // Voiceover seems to drop live region changed notifications if they come
       // too soon after a live region created notification.
       // TODO(nektar): Limit the number of changed notifications as well.
+
+      if (never_suppress_or_delay_events_for_testing_) {
+        NSAccessibilityPostNotification(
+            native_node, NSAccessibilityLiveRegionChangedNotification);
+        return;
+      }
+
       base::scoped_nsobject<BrowserAccessibilityCocoa> retained_node(
           [native_node retain]);
       BrowserThread::PostDelayedTask(
           BrowserThread::UI, FROM_HERE,
           base::Bind(
               [](base::scoped_nsobject<BrowserAccessibilityCocoa> node) {
                 if (node && [node instanceActive]) {
                   NSAccessibilityPostNotification(
                       node, NSAccessibilityLiveRegionChangedNotification);
                 }
@@ skipping 177 matching lines @@
     NSAccessibilityTextChangeValues : changes,
     NSAccessibilityTextChangeElement : native_node
   };
 }
 
 NSView* BrowserAccessibilityManagerMac::GetParentView() {
   return delegate() ? delegate()->AccessibilityGetAcceleratedWidget() : nullptr;
 }
 
 }  // namespace content