cros: Allow JS to control virtual keyboard on sign-in screen.

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 <set>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 256 matching lines @@
   gfx::Transform transform;
   transform.Translate(0, kAnimationDistance);
   container_->SetTransform(transform);
   container_->layer()->SetOpacity(kAnimationStartOrAfterHideOpacity);
 }
 
 void KeyboardController::AddObserver(KeyboardControllerObserver* observer) {
   observer_list_.AddObserver(observer);
 }
 
+bool KeyboardController::HasObserver(KeyboardControllerObserver* observer) {
+  return observer_list_.HasObserver(observer);
+}
+
 void KeyboardController::RemoveObserver(KeyboardControllerObserver* observer) {
   observer_list_.RemoveObserver(observer);
 }
 
 void KeyboardController::SetKeyboardMode(KeyboardMode mode) {
   if (keyboard_mode_ == mode)
     return;
 
   keyboard_mode_ = mode;
   // When keyboard is floating, no overscroll or resize is necessary. Sets
@@ skipping 235 matching lines @@
     int keyboard_height = GetContainerWindow()->bounds().height();
     const gfx::Rect& root_bounds = container_->GetRootWindow()->bounds();
     gfx::Rect new_bounds = root_bounds;
     new_bounds.set_y(root_bounds.height() - keyboard_height);
     new_bounds.set_height(keyboard_height);
     GetContainerWindow()->SetBounds(new_bounds);
   }
 }
 
 }  // namespace keyboard