Reland with a fix: Do not activate TrayBubbleView by default

ash/system/ime_menu/ime_menu_tray.h

Index: ash/system/ime_menu/ime_menu_tray.h
diff --git a/ash/system/ime_menu/ime_menu_tray.h b/ash/system/ime_menu/ime_menu_tray.h
index 39867fb3b54d24e6174258e2b535bafa0113deac..27351b6c4f6c8368bad60fe3d1eb6d37528f8e92 100644
--- a/ash/system/ime_menu/ime_menu_tray.h
+++ b/ash/system/ime_menu/ime_menu_tray.h
@@ -72,7 +72,12 @@ class ASH_EXPORT ImeMenuTray : public TrayBackgroundView,
   void BubbleViewDestroyed() override;
   void OnMouseEnteredView() override;
   void OnMouseExitedView() override;
+  void RegisterAccelerators(const std::vector<ui::Accelerator>& accelerators,
+                            views::TrayBubbleView* tray_bubble_view) override;
+  void UnregisterAllAccelerators(
+      views::TrayBubbleView* tray_bubble_view) override;
   base::string16 GetAccessibleNameForBubble() override;
+  bool ShouldEnableExtraKeyboardAccessibility() override;
   void HideBubble(const views::TrayBubbleView* bubble_view) override;
 
   // keyboard::KeyboardControllerObserver: