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

ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc

Index: ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
diff --git a/ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc b/ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
index 72d36daa7bb1f88c3ebfe43f1cc4103081e0c3ca..066f20d9a9e7ea7c6f20959d21bcc36646815cfb 100644
--- a/ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
+++ b/ash/common/system/chromeos/virtual_keyboard/virtual_keyboard_tray.cc
@@ -9,14 +9,17 @@
 #include "ash/common/keyboard/keyboard_ui.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/shelf_constants.h"
+#include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/shelf/wm_shelf_util.h"
 #include "ash/common/system/tray/tray_constants.h"
 #include "ash/common/system/tray/tray_utils.h"
 #include "ash/common/wm_shell.h"
+#include "ash/common/wm_window.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
+#include "ui/display/display.h"
 #include "ui/events/event.h"
 #include "ui/gfx/image/image_skia.h"
 #include "ui/gfx/paint_vector_icon.h"
@@ -27,7 +30,9 @@
 namespace ash {
 
 VirtualKeyboardTray::VirtualKeyboardTray(WmShelf* wm_shelf)
-    : TrayBackgroundView(wm_shelf), icon_(new views::ImageView) {
+    : TrayBackgroundView(wm_shelf),
+      display_id_(wm_shelf->GetWindow()->GetDisplayNearestWindow().id()),

[oshima, 2016/11/08 17:26:04]

This mapping may change. Please get this when showing the keyboard.

[yhanada, 2016/11/14 22:48:47]

Done.

+      icon_(new views::ImageView) {
   if (MaterialDesignController::IsShelfMaterial()) {
     gfx::ImageSkia image_md =
         CreateVectorIcon(gfx::VectorIconId::SHELF_KEYBOARD, kShelfIconColor);
@@ -76,7 +81,7 @@ void VirtualKeyboardTray::HideBubbleWithView(
 void VirtualKeyboardTray::ClickedOutsideBubble() {}
 
 bool VirtualKeyboardTray::PerformAction(const ui::Event& event) {
-  WmShell::Get()->keyboard_ui()->Show();
+  WmShell::Get()->keyboard_ui()->ShowInSpecificDisplay(display_id_);
   return true;
 }