Remove kDisableDownloadNotification and stop compiling shelf code on

chrome/browser/download/download_ui_controller.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/download/download_ui_controller.h"
 
 #include <utility>
 
 #include "base/callback.h"
 #include "base/stl_util.h"
@@ skipping 43 matching lines @@
   // Ones which are INTERRUPTED etc. can't be handed over to the Android
   // DownloadManager.
   if (item->GetState() != content::DownloadItem::IN_PROGRESS)
     return;
 
   // GET downloads without authentication are delegated to the Android
   // DownloadManager. Chrome is responsible for the rest.  See
   // InterceptDownloadResourceThrottle::ProcessDownloadRequest().
   content::DownloadControllerAndroid::Get()->OnDownloadStarted(item);
 }
-
-#else  // OS_ANDROID
-
+#elif !defined(OS_CHROMEOS)
 class DownloadShelfUIControllerDelegate
     : public DownloadUIController::Delegate {
  public:
   // |profile| is required to outlive DownloadShelfUIControllerDelegate.
   explicit DownloadShelfUIControllerDelegate(Profile* profile)
       : profile_(profile) {}
   ~DownloadShelfUIControllerDelegate() override {}
 
  private:
   // DownloadUIController::Delegate
@@ skipping 12 matching lines @@
   // but better than not showing the download at all.
   if (browser == nullptr)
     browser = chrome::FindLastActiveWithProfile(profile_);
 
   if (browser && browser->window() &&
       DownloadItemModel(item).ShouldShowInShelf()) {
     // GetDownloadShelf creates the download shelf if it was not yet created.
     browser->window()->GetDownloadShelf()->AddDownload(item);
   }
 }
-
-#endif  // !OS_ANDROID
+#endif
 
 } // namespace
 
 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() {
 }
 
 void DownloadUIController::OnDownloadCreated(content::DownloadManager* manager,
                                              content::DownloadItem* item) {
   // SavePackage downloads are created in a state where they can be shown in the
   // browser. Call OnDownloadUpdated() once to notify the UI immediately.
   OnDownloadUpdated(manager, item);
@@ skipping 31 matching lines @@
     }
   }
 #endif
 
   if (item->GetState() == content::DownloadItem::CANCELLED)
     return;
 
   DownloadItemModel(item).SetWasUINotified(true);
   delegate_->OnNewDownloadReady(item);
 }