Only show virtual keyboard on primary root window

ui/keyboard/keyboard_controller.h

Index: ui/keyboard/keyboard_controller.h
diff --git a/ui/keyboard/keyboard_controller.h b/ui/keyboard/keyboard_controller.h
index 31f48d3da43d2fea75de683f1fe813d5649c1871..65656a27a479c7f62c23352da43b5bc6a7856da2 100644
--- a/ui/keyboard/keyboard_controller.h
+++ b/ui/keyboard/keyboard_controller.h
@@ -38,8 +38,8 @@ class KEYBOARD_EXPORT KeyboardController : public ui::InputMethodObserver,
   explicit KeyboardController(KeyboardControllerProxy* proxy);
   virtual ~KeyboardController();
 
-  // Returns the container for the keyboard, which is then owned by the caller.
-  // It is the responsibility of the caller to Show() the returned window.
+  // Returns the container for the keyboard, which is owned by
+  // KeyboardController.
   aura::Window* GetContainerWindow();
 
   // Hides virtual keyboard and notifies observer bounds change.
@@ -58,7 +58,6 @@ class KEYBOARD_EXPORT KeyboardController : public ui::InputMethodObserver,
   // aura::WindowObserver overrides
   virtual void OnWindowHierarchyChanged(
       const HierarchyChangeParams& params) OVERRIDE;
-  virtual void OnWindowDestroying(aura::Window* window) OVERRIDE;
 
   // InputMethodObserver overrides
   virtual void OnTextInputStateChanged(
@@ -70,7 +69,7 @@ class KEYBOARD_EXPORT KeyboardController : public ui::InputMethodObserver,
   bool WillHideKeyboard() const;
 
   scoped_ptr<KeyboardControllerProxy> proxy_;
-  aura::Window* container_;
+  scoped_ptr<aura::Window> container_;
   ui::InputMethod* input_method_;
   bool keyboard_visible_;
   base::WeakPtrFactory<KeyboardController> weak_factory_;