Show "Update Chrome OS" in the wrench menu, when the update image is ready.

chrome/browser/dom_ui/options/about_page_handler.cc

Index: chrome/browser/dom_ui/options/about_page_handler.cc
diff --git a/chrome/browser/dom_ui/options/about_page_handler.cc b/chrome/browser/dom_ui/options/about_page_handler.cc
index cece7a3c7bec0ab75b18769f20e711ccd5f35748..902e71a90bfcfac2f48faa0c5f37449e875c45f1 100644
--- a/chrome/browser/dom_ui/options/about_page_handler.cc
+++ b/chrome/browser/dom_ui/options/about_page_handler.cc
@@ -33,6 +33,7 @@
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/cros/cros_library.h"
+#include "chrome/browser/chromeos/cros/power_library.h"
 #include "chrome/browser/chromeos/cros/update_library.h"
 #endif
 
@@ -66,6 +67,7 @@ const LocalizeEntry localize_table[] = {
     { "loading", IDS_ABOUT_PAGE_LOADING },
     { "check_now", IDS_ABOUT_PAGE_CHECK_NOW },
     { "update_status", IDS_UPGRADE_CHECK_STARTED },
+    { "restart_now", IDS_RESTART_AND_UPDATE },
 #else
     { "product", IDS_PRODUCT_NAME },
     { "check_now", IDS_ABOUT_CHROME_UPDATE_CHECK },
@@ -239,6 +241,8 @@ void AboutPageHandler::RegisterMessages() {
 #if defined(OS_CHROMEOS)
   dom_ui_->RegisterMessageCallback("CheckNow",
       NewCallback(this, &AboutPageHandler::CheckNow));
+  dom_ui_->RegisterMessageCallback("RestartNow",
+      NewCallback(this, &AboutPageHandler::RestartNow));
 #endif
 }
 
@@ -272,6 +276,10 @@ void AboutPageHandler::CheckNow(const ListValue* args) {
     chromeos::InitiateUpdateCheck();
 }
 
+void AboutPageHandler::RestartNow(const ListValue* args) {
+  chromeos::CrosLibrary::Get()->GetPowerLibrary()->RequestRestart();
+}
+
 void AboutPageHandler::UpdateStatus(
     const chromeos::UpdateLibrary::Status& status) {
   string16 message;
@@ -347,6 +355,10 @@ void AboutPageHandler::UpdateStatus(
     dom_ui_->CallJavascriptFunction(L"AboutPage.setUpdateImage",
                                     *image_string);
   }
+  // We'll change the "Check For Update" button to "Restart" button.
+  if (status.status == chromeos::UPDATE_STATUS_UPDATED_NEED_REBOOT) {
+    dom_ui_->CallJavascriptFunction(L"AboutPage.changeToRestartButton");
+  }
 }
 
 void AboutPageHandler::OnOSVersion(chromeos::VersionLoader::Handle handle,