Implemented a "Last Updated" field for the about page of Chrome OS.

chrome/browser/ui/webui/help/help_handler.cc

 // Copyright (c) 2012 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/help/help_handler.h"
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/string16.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/policy/browser_policy_connector.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/url_constants.h"
+#include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/web_ui.h"
 #include "content/public/common/content_client.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 #include "grit/google_chrome_strings.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "v8/include/v8.h"
 #include "webkit/glue/user_agent.h"
 #include "webkit/glue/webkit_glue.h"
 
 #if defined(OS_CHROMEOS)
+#include "base/i18n/time_formatting.h"
+#include "base/sys_info.h"
 #include "chrome/browser/chromeos/login/user_manager.h"
 #include "chrome/browser/chromeos/cros_settings.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/prefs/pref_service.h"
 #endif
 
 using base::ListValue;
+using content::BrowserThread;
 
 namespace {
 
 // Returns the browser version as a string.
 string16 BuildBrowserVersionString() {
   chrome::VersionInfo version_info;
   DCHECK(version_info.is_valid());
 
   std::string browser_version = version_info.Version();
   std::string version_modifier =
@@ skipping 29 matching lines @@
     std::string user = chromeos::UserManager::Get()->GetLoggedInUser().email();
     size_t at_pos = user.find('@');
     if (at_pos != std::string::npos && at_pos + 1 < user.length())
       domain = user.substr(user.find('@') + 1);
     return domain == g_browser_process->browser_policy_connector()->
         GetEnterpriseDomain();
   }
   return false;
 }
 
+// Retrieves the time of the last Chrome OS update and converts it to a human-
+// readable string. Note that this method uses an i18n-friendly library, so
+// the returned string will already be properly translated.
+string16 CreateLastUpdatedString() {
+  base::Time time;
+
+  if (!base::SysInfo::GetTimeLastUpdated(&time)) {
+    // If the time of the last update cannot be retrieved, punt and just set
+    // the last update time to be the current time.
+    time = base::Time::Now();
+  }
+
+  return base::TimeFormatFriendlyDate(time);
+}
+
+// Wrapper function to add the "Last Updated" string to |localized_strings|.
+// This function is called from the File thread to ensure that it does not
+// slow down the UI thread.
+void AddLastUpdatedString(DictionaryValue* localized_strings) {
+  localized_strings->SetString("lastUpdatedDate", CreateLastUpdatedString());
+}
+
 #endif  // defined(OS_CHROMEOS)
 
 }  // namespace
 
 HelpHandler::HelpHandler()
     : version_updater_(VersionUpdater::Create()) {
 }
 
 HelpHandler::~HelpHandler() {
 }
@@ skipping 26 matching lines @@
     { "firmware", IDS_ABOUT_PAGE_FIRMWARE },
     { "showMoreInfo", IDS_SHOW_MORE_INFO },
     { "hideMoreInfo", IDS_HIDE_MORE_INFO },
     { "channel", IDS_ABOUT_PAGE_CHANNEL },
     { "stable", IDS_ABOUT_PAGE_CHANNEL_STABLE },
     { "beta", IDS_ABOUT_PAGE_CHANNEL_BETA },
     { "dev", IDS_ABOUT_PAGE_CHANNEL_DEVELOPMENT },
     { "webkit", IDS_WEBKIT },
     { "userAgent", IDS_ABOUT_VERSION_USER_AGENT },
     { "commandLine", IDS_ABOUT_VERSION_COMMAND_LINE },
+    { "lastUpdated", IDS_ABOUT_VERSION_LAST_UPDATED },
 #endif
 #if defined(OS_MACOSX)
     { "promote", IDS_ABOUT_CHROME_PROMOTE_UPDATER },
 #endif
   };
 
   for (size_t i = 0; i < ARRAYSIZE_UNSAFE(resources); ++i) {
     localized_strings->SetString(resources[i].name,
                                  l10n_util::GetStringUTF16(resources[i].ids));
   }
 
   localized_strings->SetString(
       "browserVersion",
       l10n_util::GetStringFUTF16(IDS_ABOUT_PRODUCT_VERSION,
                                  BuildBrowserVersionString()));
 
   string16 license = l10n_util::GetStringFUTF16(
       IDS_ABOUT_VERSION_LICENSE,
       UTF8ToUTF16(google_util::StringAppendGoogleLocaleParam(
           chrome::kChromiumProjectURL)),
       ASCIIToUTF16(chrome::kChromeUICreditsURL));
   localized_strings->SetString("productLicense", license);
 
 #if defined(OS_CHROMEOS)
   string16 os_license = l10n_util::GetStringFUTF16(
       IDS_ABOUT_CROS_VERSION_LICENSE,
       ASCIIToUTF16(chrome::kChromeUIOSCreditsURL));
   localized_strings->SetString("productOsLicense", os_license);
+
+  BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
+      base::Bind(&AddLastUpdatedString, localized_strings));

[Evan Stade, 2012/04/16 19:42:51]

there is a race here, and besides which localized_strings is not thread safe

instead of adding the last updated time to localized_strings, you should create
a javascript function call to pass along that string. Also you should cache it,
so you only have to read from disk once

and I think you'll find FileUtilProxy to be pretty helpful

[Kyle Horimoto, 2012/04/17 18:31:45]

Done.

 #endif
 
   string16 tos = l10n_util::GetStringFUTF16(
       IDS_ABOUT_TERMS_OF_SERVICE, UTF8ToUTF16(chrome::kChromeUITermsURL));
   localized_strings->SetString("productTOS", tos);
 
   localized_strings->SetString("webkitVersion",
                                webkit_glue::GetWebKitVersion());
 
   localized_strings->SetString("jsEngine", "V8");
@@ skipping 197 matching lines @@
   web_ui()->CallJavascriptFunction("help.HelpPage.setOSFirmware",
                                    *firmware_string);
 }
 
 void HelpHandler::OnReleaseChannel(const std::string& channel) {
   scoped_ptr<Value> channel_string(Value::CreateStringValue(channel));
   web_ui()->CallJavascriptFunction(
       "help.HelpPage.updateSelectedChannel", *channel_string);
 }
 #endif // defined(OS_CHROMEOS)