Rename PlatformScreen to ScreenManager.

services/ui/display/screen_manager.cc

 // Copyright 2016 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 "services/ui/display/platform_screen.h"
+#include "services/ui/display/screen_manager.h"
 
 #include "base/logging.h"
 
 namespace display {
 
 // static
-PlatformScreen* PlatformScreen::instance_ = nullptr;
+ScreenManager* ScreenManager::instance_ = nullptr;
 
-PlatformScreen::PlatformScreen() {
+ScreenManager::ScreenManager() {
   DCHECK(!instance_);
   instance_ = this;
 }
 
-PlatformScreen::~PlatformScreen() {
+ScreenManager::~ScreenManager() {
   DCHECK_EQ(instance_, this);
   instance_ = nullptr;
 }
 
 // static
-PlatformScreen* PlatformScreen::GetInstance() {
+ScreenManager* ScreenManager::GetInstance() {
   DCHECK(instance_);
   return instance_;
 }
 
 }  // namespace display