Implement PrerenderManager::AddPrerenderForOffline()

chrome/browser/prerender/prerender_constants.h

+// Copyright (c) 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.
+
+#ifndef CHROME_BROWSER_PRERENDER_PRERENDER_CONSTANTS_H_
+#define CHROME_BROWSER_PRERENDER_PRERENDER_CONSTANTS_H_
+
+namespace prerender {
+
+// Most of the prerender are used in less than 5 minutes.
+const int kDefaultPrerenderLifeExpectancyMinutes = 5;
+
+// Offline originated prerenders have an higher life expectancy to have more
+// time to fully load web pages from slow network before the web content
+// snapshot.
+const int kOfflinePrerenderLifeExpectancyMinutes = 20;

[pasko, 2016/04/06 11:09:06]

dougarnett@ said: "5 minutes is plenty.", and the point about timeout was
removed from the doc, so this should be changed back then.

+
+}  // namespace prerender
+
+#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_CONSTANTS_H_