Add keepalive for on screen keyboard

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 1b41d557b8285a46101c3d36a2b9bbfa7e375f50..b6046e435089b9ba7d15230004f206767019408d 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -1712,7 +1712,8 @@ void RenderWidgetHostViewAura::FocusedNodeChanged(
     bool editable,
     const gfx::Rect& node_bounds_in_screen) {
 #if defined(OS_WIN)
-  if (!editable && virtual_keyboard_requested_) {
+  if (!editable && virtual_keyboard_requested_ &&
+      !node_bounds_in_screen.IsEmpty()) {
     virtual_keyboard_requested_ = false;
 
     RenderViewHost* rvh = RenderViewHost::From(host_);