Restore screen work area after login

ui/keyboard/keyboard_controller.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/keyboard/keyboard_controller.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "ui/aura/layout_manager.h"
 #include "ui/aura/window.h"
@@ skipping 254 matching lines @@
     container_->set_owned_by_parent(false);
     container_->Init(aura::WINDOW_LAYER_NOT_DRAWN);
     container_->AddObserver(this);
     container_->SetLayoutManager(new KeyboardLayoutManager(this));
   }
   return container_.get();
 }
 
 void KeyboardController::NotifyKeyboardBoundsChanging(
     const gfx::Rect& new_bounds) {
-  if (proxy_->GetKeyboardWindow()->IsVisible()) {
+  if (proxy_->HasKeyboardWindow() && proxy_->GetKeyboardWindow()->IsVisible()) {
     FOR_EACH_OBSERVER(KeyboardControllerObserver,
                       observer_list_,
                       OnKeyboardBoundsChanging(new_bounds));
   }
 }
 
 void KeyboardController::HideKeyboard(HideReason reason) {
   keyboard_visible_ = false;
 
   keyboard::LogKeyboardControlEvent(
@@ skipping 164 matching lines @@
   // background during animation.
   NotifyKeyboardBoundsChanging(proxy_->GetKeyboardWindow()->bounds());
   proxy_->EnsureCaretInWorkArea();
 }
 
 void KeyboardController::HideAnimationFinished() {
   proxy_->HideKeyboardContainer(container_.get());
 }
 
 }  // namespace keyboard