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

ui/keyboard/keyboard_layout_delegate.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef UI_KEYBOARD_KEYBOARD_LAYOUT_DELEGATE_H_
+#define UI_KEYBOARD_KEYBOARD_LAYOUT_DELEGATE_H_
+
+#include <stdint.h>
+
+#include "ui/keyboard/keyboard_export.h"
+
+namespace keyboard {
+
+// A delegate class to control the virtual keyboard layout
+class KEYBOARD_EXPORT KeyboardLayoutDelegate {
+ public:
+  virtual ~KeyboardLayoutDelegate() {}
+
+  virtual void MoveKeyboardToDisplay(int64_t display_id) = 0;
+
+  // Move the keyboard to the touchable display which has the input focus, or
+  // the first touchable display.
+  virtual void MoveKeyboardToTouchableDisplay() = 0;
+};
+
+}  // namespace keyboard
+
+#endif