Implement PrerenderManager::AddPrerenderForOffline()

chrome/browser/prerender/prerender_origin.cc

 // Copyright (c) 2012 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/prerender/prerender_origin.h"
 
 #include "base/macros.h"
 #include "base/metrics/histogram.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 
 namespace prerender {
 
 namespace {
 
 const char* kOriginNames[] = {
   "[Deprecated] Link Rel Prerender (original)",
   "[Deprecated] Omnibox (original)",
   "GWS Prerender",
   "[Deprecated] Omnibox (conservative)",
   "[Deprecated] Omnibox (exact)",
   "Omnibox",
   "None",
   "Link Rel Prerender (same domain)",
   "Link Rel Prerender (cross domain)",
   "Local Predictor",
   "External Request",
   "Instant",
   "Link Rel Next",
   "External Request Forced Cellular",
+  "Offline",
   "Max",
 };
 static_assert(arraysize(kOriginNames) == ORIGIN_MAX + 1,
               "prerender origin name count mismatch");
 
 }  // namespace
 
 const char* NameFromOrigin(Origin origin) {
   DCHECK(static_cast<int>(origin) >= 0 &&
          origin <= ORIGIN_MAX);
   return kOriginNames[origin];
 }
 
+bool IsAlwaysPrerenderedOrigin(Origin origin) {
+  DCHECK(static_cast<int>(origin) >= 0 &&
+         origin < ORIGIN_MAX);
+  // <link rel=prerender> origins ignore the network state and the privacy
+  // settings. Web developers should be able prefetch with all possible privacy
+  // settings and with all possible network types. This would avoid web devs
+  // coming up with creative ways to prefetch in cases they are not allowed to
+  // do so.
+  //
+  // Offline originated prerenders also ignore the network state and privacy
+  // settings because want to be able to snapshot webpages independently of
+  // these former settings.
+  return origin == ORIGIN_LINK_REL_PRERENDER_SAMEDOMAIN ||
+         origin == ORIGIN_LINK_REL_PRERENDER_CROSSDOMAIN ||
+         origin == ORIGIN_OFFLINE;
+}
+
+bool IsCellularForcedOrigin(Origin origin) {
+  DCHECK(static_cast<int>(origin) >= 0 &&
+         origin < ORIGIN_MAX);
+  return origin == ORIGIN_EXTERNAL_REQUEST_FORCED_CELLULAR ||
+         IsAlwaysPrerenderedOrigin(origin);
+}
+
 }  // namespace prerender