Add back button to chrome://devices

chrome/browser/ui/webui/local_discovery/local_discovery_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/local_discovery/local_discovery_ui.h"
 
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/webui/local_discovery/local_discovery_ui_handler.h"
 #include "chrome/browser/ui/webui/metrics_handler.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
+#include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/browser/web_ui_data_source.h"
 #include "grit/browser_resources.h"
 #include "grit/generated_resources.h"
 
 namespace {
 
 content::WebUIDataSource* CreateLocalDiscoveryHTMLSource() {
   content::WebUIDataSource* source =
       content::WebUIDataSource::Create(chrome::kChromeUIDevicesHost);
@@ skipping 55 matching lines @@
   source->AddLocalizedString("cloudDevicesNeedLogin",
                              IDS_LOCAL_DISCOVERY_CLOUD_DEVICES_NEED_LOGIN);
   source->AddLocalizedString("cloudDevicesLogin",
                              IDS_LOCAL_DISCOVERY_CLOUD_DEVICES_LOGIN);
   source->AddLocalizedString("registerNeedLogin",
                              IDS_LOCAL_DISCOVERY_REGISTER_NEED_LOGIN);
   source->AddLocalizedString("availableDevicesTitle",
                              IDS_LOCAL_DISCOVERY_AVAILABLE_DEVICES);
   source->AddLocalizedString("myDevicesTitle",
                              IDS_LOCAL_DISCOVERY_MY_DEVICES);
-
+  source->AddLocalizedString("backButton", IDS_SETTINGS_TITLE);
 
   // Cloud print connector-related strings.
 #if defined(ENABLE_FULL_PRINTING) && !defined(OS_CHROMEOS)
   source->AddLocalizedString("cloudPrintConnectorEnablingButton",
                              IDS_OPTIONS_CLOUD_PRINT_CONNECTOR_ENABLING_BUTTON);
   source->AddLocalizedString("cloudPrintConnectorDisabledButton",
                              IDS_OPTIONS_CLOUD_PRINT_CONNECTOR_DISABLED_BUTTON);
   source->AddLocalizedString("cloudPrintConnectorEnabledButton",
                              IDS_OPTIONS_CLOUD_PRINT_CONNECTOR_ENABLED_BUTTON);
   source->AddLocalizedString("cloudPrintName",
                              IDS_GOOGLE_CLOUD_PRINT);
   source->AddLocalizedString("titleConnector",
                              IDS_LOCAL_DISCOVERY_CONNECTOR_SECTION);
 #endif
 
   source->SetJsonPath("strings.js");
 
   source->DisableDenyXFrameOptions();
 
   return source;
 }
 
 }  // namespace
 
 LocalDiscoveryUI::LocalDiscoveryUI(content::WebUI* web_ui)
     : WebUIController(web_ui) {
   // Set up the chrome://devices/ source.
-  Profile* profile = Profile::FromWebUI(web_ui);
-  content::WebUIDataSource::Add(profile, CreateLocalDiscoveryHTMLSource());
+  content::WebUIDataSource* source = CreateLocalDiscoveryHTMLSource();
+  Browser* browser =
+      chrome::FindBrowserWithWebContents(web_ui->GetWebContents());
+  // Show a back button pointing to Settings if the browser has no location bar.
+  if (browser && browser->is_trusted_source())
+    source->AddString("backButtonURL", chrome::kChromeUISettingsURL);
+  content::WebUIDataSource::Add(Profile::FromWebUI(web_ui), source);
 
   // TODO(gene): Use LocalDiscoveryUIHandler to send updated to the devices
   // page. For example
   web_ui->AddMessageHandler(new local_discovery::LocalDiscoveryUIHandler());
   web_ui->AddMessageHandler(new MetricsHandler());
 }
 
 void LocalDiscoveryUI::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   registry->RegisterBooleanPref(
       prefs::kLocalDiscoveryNotificationsEnabled,
 #if defined(OS_WIN)
       false,
 #else
       true,
 #endif
       user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
 }