Suppress accessibility events when user is navigating away.

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 ae4f0899749f678aa3eaa0b74ceaf52f02612ce3..79d936182af5b7001d085fd4f8e58063ddd46dc1 100644
--- a/content/browser/accessibility/browser_accessibility_manager_win.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_win.cc
@@ -179,6 +179,10 @@ void BrowserAccessibilityManagerWin::OnWindowFocused() {
   BrowserAccessibilityManager::OnWindowFocused();
 }
 
+void BrowserAccessibilityManagerWin::UserIsReloading() {
+  MaybeCallNotifyWinEvent(IA2_EVENT_DOCUMENT_RELOAD, GetRoot());
+}
+
 void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
     ui::AXEvent event_type,
     BrowserAccessibility* node) {
@@ -188,6 +192,11 @@ void BrowserAccessibilityManagerWin::NotifyAccessibilityEvent(
     return;
   }
 
+  // Don't fire events when this document might be stale as the user has
+  // started navigating to a new document.
+  if (user_is_navigating_away_)
+    return;
+
   // Inline text boxes are an internal implementation detail, we don't
   // expose them to Windows.
   if (node->GetRole() == ui::AX_ROLE_INLINE_TEXT_BOX)