Make the virtual keyboard show up on the display with input focus.

ash/common/keyboard/keyboard_ui.cc

Index: ash/common/keyboard/keyboard_ui.cc
diff --git a/ash/common/keyboard/keyboard_ui.cc b/ash/common/keyboard/keyboard_ui.cc
index 25ecbd8893b0f812dcbac8b8660029edfc99735d..37fcc445cb6cd068561163490dac72a073937dc8 100644
--- a/ash/common/keyboard/keyboard_ui.cc
+++ b/ash/common/keyboard/keyboard_ui.cc
@@ -30,6 +30,10 @@ class KeyboardUIImpl : public KeyboardUI, public AccessibilityObserver {
   void Show() override {
     keyboard::KeyboardController::GetInstance()->ShowKeyboard(true);
   }
+  void ShowInDisplay(const int64_t display_id) override {
+    keyboard::KeyboardController::GetInstance()->ShowKeyboardInDisplay(
+        display_id);
+  }
   void Hide() override {
     // Do nothing as this is called from ash::Shell, which also calls through
     // to the appropriate keyboard functions.