text input focus: Supports Window::GetFocusedTextInputClient.

ui/aura/window.cc

Index: ui/aura/window.cc
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index 91df99eefcdfb8dbd07b9f66e5522c71b069a59a..ab1a2da85fca8ff6911f10333006355627a5c03e 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -647,6 +647,10 @@ void Window::ConvertRectToTarget(const Window* source,
   rect->set_origin(origin);
 }
 
+ui::TextInputClient* Window::GetFocusedTextInputClient() {
+  return delegate_ ? delegate_->GetFocusedTextInputClient() : nullptr;
+}
+
 void Window::MoveCursorTo(const gfx::Point& point_in_window) {
   Window* root_window = GetRootWindow();
   DCHECK(root_window);