(Merge to M-51) Revise the shelf alignment locking mechanism.

chrome/browser/ui/webui/chromeos/first_run/first_run_ui.cc

 // Copyright 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 "chrome/browser/ui/webui/chromeos/first_run/first_run_ui.h"
 
-#include "ash/shell.h"
+#include "ash/shelf/shelf.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/chromeos/first_run/first_run_handler.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
 #include "chromeos/chromeos_switches.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/browser/web_ui_data_source.h"
@@ skipping 36 matching lines @@
       l10n_util::GetStringUTF16(IDS_FIRST_RUN_HELP_STEP_KEEP_EXPLORING_BUTTON));
   localized_strings->SetString(
       "helpFinishButton",
       l10n_util::GetStringUTF16(IDS_FIRST_RUN_HELP_STEP_FINISH_BUTTON));
   localized_strings->SetString(
       "nextButton", l10n_util::GetStringUTF16(IDS_FIRST_RUN_NEXT_BUTTON));
   localized_strings->SetBoolean(
       "transitionsEnabled",
       base::CommandLine::ForCurrentProcess()->HasSwitch(
           chromeos::switches::kEnableFirstRunUITransitions));
-  std::string shelf_alignment;
-  ash::Shell* shell = ash::Shell::GetInstance();
-  switch (shell->GetShelfAlignment(shell->GetPrimaryRootWindow())) {
-    case ash::SHELF_ALIGNMENT_BOTTOM:
-      shelf_alignment = kShelfAlignmentBottom;
-      break;
-    case ash::SHELF_ALIGNMENT_LEFT:
-      shelf_alignment = kShelfAlignmentLeft;
-      break;
-    case ash::SHELF_ALIGNMENT_RIGHT:
-      shelf_alignment = kShelfAlignmentRight;
-      break;
-    default:
-      NOTREACHED() << "Unsupported shelf alignment";
-  }
+  const std::string& shelf_alignment =
+      ash::Shelf::ForPrimaryDisplay()->SelectValueForShelfAlignment(
+          kShelfAlignmentBottom, kShelfAlignmentLeft, kShelfAlignmentRight);
   localized_strings->SetString("shelfAlignment", shelf_alignment);
 }
 
 content::WebUIDataSource* CreateDataSource() {
   content::WebUIDataSource* source =
       content::WebUIDataSource::Create(chrome::kChromeUIFirstRunHost);
   source->SetJsonPath("strings.js");
   source->SetDefaultResource(IDR_FIRST_RUN_HTML);
   source->AddResourcePath(kFirstRunJSPath, IDR_FIRST_RUN_JS);
   base::DictionaryValue localized_strings;
@@ skipping 12 matching lines @@
     : WebUIController(web_ui),
       actor_(NULL) {
   FirstRunHandler* handler = new FirstRunHandler();
   actor_ = handler;
   web_ui->AddMessageHandler(handler);
   content::WebUIDataSource::Add(Profile::FromWebUI(web_ui), CreateDataSource());
 }
 
 }  // namespace chromeos