Fire an alert event to notify accessibility when a permissions bubble gets shown.

ui/views/bubble/bubble_delegate.cc

Index: ui/views/bubble/bubble_delegate.cc
diff --git a/ui/views/bubble/bubble_delegate.cc b/ui/views/bubble/bubble_delegate.cc
index 55ce980289149c322219d60e35222009d4ee8614..8073040c58701262f93143ffba70a9cdc90f65ef 100644
--- a/ui/views/bubble/bubble_delegate.cc
+++ b/ui/views/bubble/bubble_delegate.cc
@@ -300,10 +300,12 @@ void BubbleDelegateView::UpdateColorsFromTheme(const ui::NativeTheme* theme) {
 void BubbleDelegateView::HandleVisibilityChanged(Widget* widget, bool visible) {
   if (widget == GetWidget() && anchor_widget() &&
       anchor_widget()->GetTopLevelWidget()) {
-    if (visible)
+    if (visible) {
       anchor_widget()->GetTopLevelWidget()->DisableInactiveRendering();
-    else
+      NotifyAccessibilityEvent(ui::AX_EVENT_ALERT, true);

[msw, 2015/04/06 17:30:19]

Most bubbles should have an anchor, but I suspect that firing this event
shouldn't be contingent on the presence of an anchor widget (nor that object's
top level widget).

[David Tseng, 2015/04/06 17:36:05]

Done.

+    } else {
       anchor_widget()->GetTopLevelWidget()->EnableInactiveRendering();
+    }
   }
 }