Remove kDisableDownloadNotification and stop compiling shelf code on

chrome/browser/download/download_ui_controller.cc

Index: chrome/browser/download/download_ui_controller.cc
diff --git a/chrome/browser/download/download_ui_controller.cc b/chrome/browser/download/download_ui_controller.cc
index e0bb05bf48dfffa2fd1a5d3262e4e7e30c74580c..9d7c07e739acbb0d87cbc2bd609be460f8404cc4 100644
--- a/chrome/browser/download/download_ui_controller.cc
+++ b/chrome/browser/download/download_ui_controller.cc
@@ -61,9 +61,7 @@ void AndroidUIControllerDelegate::OnNewDownloadReady(
   // InterceptDownloadResourceThrottle::ProcessDownloadRequest().
   content::DownloadControllerAndroid::Get()->OnDownloadStarted(item);
 }
-
-#else  // OS_ANDROID
-
+#elif !defined(OS_CHROMEOS)
 class DownloadShelfUIControllerDelegate
     : public DownloadUIController::Delegate {
  public:
@@ -96,8 +94,7 @@ void DownloadShelfUIControllerDelegate::OnNewDownloadReady(
     browser->window()->GetDownloadShelf()->AddDownload(item);
   }
 }
-
-#endif  // !OS_ANDROID
+#endif
 
 } // namespace
 
@@ -107,23 +104,19 @@ DownloadUIController::Delegate::~Delegate() {
 DownloadUIController::DownloadUIController(content::DownloadManager* manager,
                                            scoped_ptr<Delegate> delegate)
     : download_notifier_(manager, this), delegate_(std::move(delegate)) {
+  if (!delegate_) {
 #if defined(OS_ANDROID)
-  if (!delegate_)
     delegate_.reset(new AndroidUIControllerDelegate());
-#else
-#if defined(OS_CHROMEOS)
-  if (!delegate_ && DownloadNotificationManager::IsEnabled()) {
+#elif defined(OS_CHROMEOS)
     // The Profile is guaranteed to be valid since DownloadUIController is owned
     // by DownloadService, which in turn is a profile keyed service.
     delegate_.reset(new DownloadNotificationManager(
         Profile::FromBrowserContext(manager->GetBrowserContext())));
-  }
-#endif  // defined(OS_CHROMEOS)
-  if (!delegate_) {
+#else
     delegate_.reset(new DownloadShelfUIControllerDelegate(
         Profile::FromBrowserContext(manager->GetBrowserContext())));
+#endif
   }
-#endif  // defined(OS_ANDROID)
 }
 
 DownloadUIController::~DownloadUIController() {