Downloads: Added transient flag to download item and download database

chrome/browser/ntp_snippets/fake_download_item.cc

 // Copyright 2016 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/ntp_snippets/fake_download_item.h"
 
 #include "base/bind.h"
 
 using content::DownloadItem;
 
@@ skipping 350 matching lines @@
 bool FakeDownloadItem::GetOpened() const {
   NOTREACHED();
   return false;
 }
 
 base::Time FakeDownloadItem::GetLastAccessTime() const {
   NOTREACHED();
   return base::Time();
 }
 
+bool FakeDownloadItem::IsVisible() const {
+  NOTREACHED();
+  return true;
+}
+
 content::BrowserContext* FakeDownloadItem::GetBrowserContext() const {
   NOTREACHED();
   return nullptr;
 }
 
 content::WebContents* FakeDownloadItem::GetWebContents() const {
   NOTREACHED();
   return nullptr;
 }
 
@@ skipping 17 matching lines @@
 void FakeDownloadItem::SetDisplayName(const base::FilePath& name) {
   NOTREACHED();
 }
 
 std::string FakeDownloadItem::DebugString(bool verbose) const {
   NOTREACHED();
   return std::string();
 }
 
 }  // namespace test