Uses the activedescendant_changed event received from Blink to fire the right focus event

content/browser/accessibility/browser_accessibility_manager_win.cc

Index: content/browser/accessibility/browser_accessibility_manager_win.cc
diff --git a/content/browser/accessibility/browser_accessibility_manager_win.cc b/content/browser/accessibility/browser_accessibility_manager_win.cc
index eb9a2e4db2101e7eec5e037241d0f0230fbb19f2..57beb91e694c9d47070bec05cfe258a1eadd4fa3 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_win.cc
@@ -137,6 +137,9 @@ void BrowserAccessibilityManagerWin::UserIsReloading() {
 void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
     ui::AXEvent event_type,
     BrowserAccessibility* node) {
+  if (!node)
+    return;
+
   BrowserAccessibilityDelegate* root_delegate = GetDelegateFromRootManager();
   if (!root_delegate || !root_delegate->AccessibilityGetAcceleratedWidget()) {
     DLOG(WARNING) << "Not firing AX event because of no root_delegate or hwnd";
@@ -165,9 +168,13 @@ void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
 
   LONG event_id = EVENT_MIN;
   switch (event_type) {
-    case ui::AX_EVENT_ACTIVEDESCENDANTCHANGED:
+    case ui::AX_EVENT_ACTIVEDESCENDANTCHANGED: {
       event_id = IA2_EVENT_ACTIVE_DESCENDANT_CHANGED;
+      BrowserAccessibility* active_descendant = GetActiveDescendantFocus(node);
+      if (active_descendant != node)
+        FireFocusEvent(active_descendant);
       break;
+    }
     case ui::AX_EVENT_ALERT:
       event_id = EVENT_SYSTEM_ALERT;
       break;
@@ -217,9 +224,6 @@ void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
       break;
   }
 
-  if (!node)
-    return;
-
   if (event_id != EVENT_MIN)
     MaybeCallNotifyWinEvent(event_id, node);
 
@@ -246,6 +250,7 @@ bool BrowserAccessibilityManagerWin::CanFireEvents() {
 
 void BrowserAccessibilityManagerWin::FireFocusEvent(
     BrowserAccessibility* node) {
+  DCHECK(node);
   // On Windows, we always fire a FOCUS event on the root of a frame before
   // firing a focus event within that frame.
   if (node->manager() != last_focused_manager_ &&