Implement overscroll support for the virtual keyboard.

ash/shelf/shelf_layout_manager.h

Index: ash/shelf/shelf_layout_manager.h
diff --git a/ash/shelf/shelf_layout_manager.h b/ash/shelf/shelf_layout_manager.h
index 4e03c7aa5d1ed43c7a4136a749f855c23fe41a52..8832f128df396e122937dafdf9ec1964bcc15a8b 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -21,11 +21,11 @@
 #include "base/logging.h"
 #include "base/observer_list.h"
 #include "base/timer/timer.h"
+#include "ui/aura/client/virtual_keyboard_observer.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/gfx/insets.h"
 #include "ui/gfx/rect.h"
 #include "ui/keyboard/keyboard_controller.h"
-#include "ui/keyboard/keyboard_controller_observer.h"
 #include "ui/wm/public/activation_change_observer.h"
 
 namespace aura {
@@ -61,8 +61,8 @@ class ASH_EXPORT ShelfLayoutManager :
     public aura::LayoutManager,
     public ash::ShellObserver,
     public aura::client::ActivationChangeObserver,
+    public aura::client::VirtualKeyboardObserver,
     public DockedWindowLayoutManagerObserver,
-    public keyboard::KeyboardControllerObserver,
     public LockStateObserver {
  public:
 
@@ -330,7 +330,7 @@ class ASH_EXPORT ShelfLayoutManager :
   // of the keyboard if necessary.
   gfx::Rect GetAvailableBounds() const;
 
-  // Overridden from keyboard::KeyboardControllerObserver:
+  // Overridden from aura::client::VirtualKeyboardObserver:
   virtual void OnKeyboardBoundsChanging(
       const gfx::Rect& keyboard_bounds) OVERRIDE;