text input focus: Supports Window::GetFocusedTextInputClient.

ui/views/controls/native/native_view_host_aura.cc

Index: ui/views/controls/native/native_view_host_aura.cc
diff --git a/ui/views/controls/native/native_view_host_aura.cc b/ui/views/controls/native/native_view_host_aura.cc
index 9cba9618c870ec0b727358eab2bc0033a40110af..a1d73ef0b632143da3afb9e7547ed3f663f702ff 100644
--- a/ui/views/controls/native/native_view_host_aura.cc
+++ b/ui/views/controls/native/native_view_host_aura.cc
@@ -30,6 +30,7 @@ class NativeViewHostAura::ClippingWindowDelegate : public aura::WindowDelegate {
   gfx::Size GetMaximumSize() const override { return gfx::Size(); }
   void OnBoundsChanged(const gfx::Rect& old_bounds,
                        const gfx::Rect& new_bounds) override {}
+  ui::TextInputClient* GetFocusedTextInputClient() override { return nullptr; }
   gfx::NativeCursor GetCursor(const gfx::Point& point) override {
     return gfx::kNullCursor;
   }