Make keyboard controller a singleton.

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/window.h"
 #include "ui/aura/window_delegate.h"
@@ skipping 162 matching lines @@
     return;
   animator_->RemoveObserver(this);
   callback_.Run();
 }
 
 void CallbackAnimationObserver::OnLayerAnimationAborted(
     ui::LayerAnimationSequence* seq) {
   animator_->RemoveObserver(this);
 }
 
+// static
+KeyboardController* KeyboardController::instance_ = NULL;
+
 KeyboardController::KeyboardController(KeyboardControllerProxy* proxy)
     : proxy_(proxy),
       input_method_(NULL),
       keyboard_visible_(false),
       lock_keyboard_(false),
       type_(ui::TEXT_INPUT_TYPE_NONE),
       weak_factory_(this) {
   CHECK(proxy);
   input_method_ = proxy_->GetInputMethod();
   input_method_->AddObserver(this);
 }
 
 KeyboardController::~KeyboardController() {
   if (container_)
     container_->RemoveObserver(this);
   if (input_method_)
     input_method_->RemoveObserver(this);
 }
 
+// static
+void KeyboardController::ResetInstance(KeyboardController* controller) {
+  if (instance_ && instance_ != controller)
+    delete instance_;
+  instance_ = controller;
+}
+
+// static
+KeyboardController* KeyboardController::GetInstance() {
+  return instance_;
+}
+
 aura::Window* KeyboardController::GetContainerWindow() {
   if (!container_.get()) {
     container_.reset(new aura::Window(
         new KeyboardWindowDelegate(proxy_.get())));
     container_->SetEventTargeter(scoped_ptr<ui::EventTargeter>(
         new KeyboardContainerTargeter(container_.get(), proxy_.get())));
     container_->SetName("KeyboardContainer");
     container_->set_owned_by_parent(false);
     container_->Init(aura::WINDOW_LAYER_NOT_DRAWN);
     container_->AddObserver(this);
@@ skipping 199 matching lines @@
   // background during animation.
   NotifyKeyboardBoundsChanging(proxy_->GetKeyboardWindow()->bounds());
   proxy_->EnsureCaretInWorkArea();
 }
 
 void KeyboardController::HideAnimationFinished() {
   proxy_->HideKeyboardContainer(container_.get());
 }
 
 }  // namespace keyboard