ash: Move VirtualKeyboardStateObserver functionality to ShellObserver

ash/wm/lock_layout_manager.cc

Index: ash/wm/lock_layout_manager.cc
diff --git a/ash/wm/lock_layout_manager.cc b/ash/wm/lock_layout_manager.cc
index e8d7da91c3b65fc3a4a99b9d770aea1303cdc0d5..5203dd3a55ae383b6f705fa1dc18b6c9b1298a7e 100644
--- a/ash/wm/lock_layout_manager.cc
+++ b/ash/wm/lock_layout_manager.cc
@@ -4,7 +4,6 @@
 
 #include "ash/wm/lock_layout_manager.h"
 
-#include "ash/common/shell_delegate.h"
 #include "ash/common/wm/window_state.h"
 #include "ash/common/wm/wm_event.h"
 #include "ash/common/wm_shell.h"
@@ -23,7 +22,7 @@ LockLayoutManager::LockLayoutManager(aura::Window* window)
       window_(window),
       root_window_(window->GetRootWindow()),
       is_observing_keyboard_(false) {
-  WmShell::Get()->delegate()->AddVirtualKeyboardStateObserver(this);
+  WmShell::Get()->AddShellObserver(this);
   root_window_->AddObserver(this);
   if (keyboard::KeyboardController::GetInstance()) {
     keyboard::KeyboardController::GetInstance()->AddObserver(this);
@@ -40,7 +39,7 @@ LockLayoutManager::~LockLayoutManager() {
     (*it)->RemoveObserver(this);
   }
 
-  WmShell::Get()->delegate()->RemoveVirtualKeyboardStateObserver(this);
+  WmShell::Get()->RemoveShellObserver(this);
 
   if (keyboard::KeyboardController::GetInstance() && is_observing_keyboard_) {
     keyboard::KeyboardController::GetInstance()->RemoveObserver(this);