Adds AXExpandedChanged for general roles.

content/browser/accessibility/accessibility_event_recorder_mac.mm

 // Copyright (c) 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.
 
 #include "content/browser/accessibility/accessibility_event_recorder.h"
 
 #include <string>
 
 #import <Cocoa/Cocoa.h>
 
@@ skipping 65 matching lines @@
   if (!application_.get())
     LOG(FATAL) << "Failed to create AXUIElement for application.";
 
   // Add the notifications we care about to the observer.
   AddNotification(NSAccessibilityFocusedUIElementChangedNotification);
   AddNotification(NSAccessibilityRowCountChangedNotification);
   AddNotification(NSAccessibilitySelectedChildrenChangedNotification);
   AddNotification(NSAccessibilitySelectedRowsChangedNotification);
   AddNotification(NSAccessibilitySelectedTextChangedNotification);
   AddNotification(NSAccessibilityValueChangedNotification);
+  AddNotification(@"AXExpandedChanged");
   AddNotification(@"AXLayoutComplete");
   AddNotification(@"AXLiveRegionChanged");
   AddNotification(@"AXLoadComplete");
   AddNotification(@"AXRowCollapsed");
   AddNotification(@"AXRowExpanded");
 
   // Add the observer to the current message loop.
   observer_run_loop_source_ = AXObserverGetRunLoopSource(observer_ref_.get());
   CFRunLoopAddSource(CFRunLoopGetCurrent(), observer_run_loop_source_,
                      kCFRunLoopDefaultMode);
@@ skipping 47 matching lines @@
 
   std::string value =
       GetAXAttributeValue(element, NSAccessibilityValueAttribute);
   if (!value.empty())
     log += base::StringPrintf(" AXValue=\"%s\"", value.c_str());
 
   event_logs_.push_back(log);
 }
 
 }  // namespace content