Added a class acting as a fake caret for accessibility.

ui/accessibility/platform/ax_platform_node_win.cc

Index: ui/accessibility/platform/ax_platform_node_win.cc
diff --git a/ui/accessibility/platform/ax_platform_node_win.cc b/ui/accessibility/platform/ax_platform_node_win.cc
index d811182f2f17fceaac6f803e3c159df170953c28..8d36b590b1e95df9b3de4691c2c07234ccce1c86 100644
--- a/ui/accessibility/platform/ax_platform_node_win.cc
+++ b/ui/accessibility/platform/ax_platform_node_win.cc
@@ -181,6 +181,12 @@ void AXPlatformNodeWin::NotifyAccessibilityEvent(ui::AXEvent event_type) {
 
   ::NotifyWinEvent(native_event, hwnd, OBJID_CLIENT, -unique_id_);
 
+  if (event_type == ui::AX_EVENT_TEXT_SELECTION_CHANGED) {
+    // We also need to fire an older MSAA event used by some assistive software.

[dougt, 2017/03/28 15:23:44]

Nit: comment is odd here since we're not dispatching any events after this

+    ::NotifyWinEvent(EVENT_OBJECT_LOCATIONCHANGE, hwnd, OBJID_CARET,
+                     -unique_id_);
+  }
+
   // Keep track of objects that are a target of an alert event.
   if (event_type == ui::AX_EVENT_ALERT)
     AddAlertTarget();