Redesigns the text input focus handling.

ui/base/ime/text_input_focus_manager.cc

+// Copyright 2014 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/base/ime/text_input_focus_manager.h"
+
+#include "base/logging.h"
+#include "base/memory/singleton.h"
+
+namespace ui {
+
+TextInputFocusManager* TextInputFocusManager::GetInstance() {
+  TextInputFocusManager* instance = Singleton<TextInputFocusManager>::get();
+  DCHECK(instance->thread_checker_.CalledOnValidThread());
+  return instance;
+}
+
+TextInputClient* TextInputFocusManager::GetFocusedTextInputClient() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  return focused_text_input_client_;
+}
+
+void TextInputFocusManager::FocusTextInputClient(
+    TextInputClient* text_input_client) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  focused_text_input_client_ = text_input_client;
+}
+
+void TextInputFocusManager::BlurTextInputClient(
+    TextInputClient* text_input_client) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (focused_text_input_client_ == text_input_client)
+    focused_text_input_client_ = NULL;
+}
+
+TextInputFocusManager::TextInputFocusManager()
+    : focused_text_input_client_(NULL) {}
+
+TextInputFocusManager::~TextInputFocusManager() {}
+
+}  // namespace ui