Hide virtual keyboard on login/lock screen when shelf button gets focus

Bug: 1043903
Change-Id: Ie5cf4ce7f0465e538b077e25b472d545014eb9d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2403285Reviewed-by: Roman Sorokin [CET] <rsorokin@chromium.org>
Commit-Queue: Thomas Tellier <tellier@google.com>
Cr-Commit-Position: refs/heads/master@{#807017}

ash/shelf/login_shelf_view.cc

@@ -10,6 +10,7 @@
 #include <utility>
 
 #include "ash/focus_cycler.h"
+#include "ash/keyboard/ui/keyboard_ui_controller.h"
 #include "ash/lock_screen_action/lock_screen_action_background_state.h"
 #include "ash/login/login_screen_controller.h"
 #include "ash/login/ui/lock_screen.h"
@@ -248,6 +249,12 @@ class LoginShelfButton : public views::LabelButton {
     SchedulePaint();
   }
 
+  void OnFocus() override {
+    auto* const keyboard_controller = keyboard::KeyboardUIController::Get();
+    keyboard_controller->set_keyboard_locked(false /*lock*/);
+    keyboard_controller->HideKeyboardImplicitlyByUser();
+  }
+
  private:
   const int text_resource_id_;
   const gfx::VectorIcon& icon_;