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

ash/virtual_keyboard_controller.h

Index: ash/virtual_keyboard_controller.h
diff --git a/ash/virtual_keyboard_controller.h b/ash/virtual_keyboard_controller.h
index fc8d4872e5b4a47a1bc4cd87424b41c289e32814..9f04454e931b8f9e93764c524a456b4220acbe89 100644
--- a/ash/virtual_keyboard_controller.h
+++ b/ash/virtual_keyboard_controller.h
@@ -5,17 +5,21 @@
 #ifndef ASH_VIRTUAL_KEYBOARD_CONTROLLER_H_
 #define ASH_VIRTUAL_KEYBOARD_CONTROLLER_H_
 
+#include <stdint.h>
+
 #include "ash/ash_export.h"
 #include "ash/common/shell_observer.h"
 #include "base/macros.h"
 #include "ui/events/devices/input_device_event_observer.h"
+#include "ui/keyboard/keyboard_layout_delegate.h"
 
 namespace ash {
 
 // This class observes input device changes for the virtual keyboard.
 class ASH_EXPORT VirtualKeyboardController
     : public ShellObserver,
-      public ui::InputDeviceEventObserver {
+      public ui::InputDeviceEventObserver,
+      public keyboard::KeyboardLayoutDelegate {
  public:
   VirtualKeyboardController();
   ~VirtualKeyboardController() override;
@@ -33,6 +37,9 @@ class ASH_EXPORT VirtualKeyboardController
   // when determining whether or not to show the on-screen keyboard.
   void ToggleIgnoreExternalKeyboard();
 
+  // keyboard::KeyboardLayoutDelegate
+  void MoveKeyboardToAnotherDisplayIfNeeded(int64_t display_id) override;
+
  private:
   // Updates the list of active input devices.
   void UpdateDevices();
@@ -43,6 +50,8 @@ class ASH_EXPORT VirtualKeyboardController
   // Creates the keyboard if |enabled|, else destroys it.
   void SetKeyboardEnabled(bool enabled);
 
+  void MoveKeyboardToFirstTouchableDisplay() const;
+
   // True if an external keyboard is connected.
   bool has_external_keyboard_;
   // True if an internal keyboard is connected.