chrome/browser/prefetch/prefetch.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/prefetch/prefetch.h"
   6
   7 #include <string>
   8
   9 #include "base/metrics/field_trial.h"
  10 #include "base/strings/string_util.h"
  11 #include "chrome/browser/net/prediction_options.h"
  12 #include "chrome/browser/prefetch/prefetch_field_trial.h"
  13 #include "chrome/browser/profiles/profile_io_data.h"
  14 #include "net/base/network_change_notifier.h"
  15
  16 namespace prefetch {
  17
  18 bool IsPrefetchEnabled(content::ResourceContext* resource_context) {
  19   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
  20
  21   ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
  22   DCHECK(io_data);
  23
  24   // TODO(bnc): Remove this condition once the new
  25   // predictive preference is used on all platforms. See crbug.com/334602.
  26   if (io_data->network_prediction_options()->GetValue() ==
  27           chrome_browser_net::NETWORK_PREDICTION_UNSET &&
  28       net::NetworkChangeNotifier::IsConnectionCellular(
  29           net::NetworkChangeNotifier::GetConnectionType())) {
  30     return false;
  31   }
  32
  33   return chrome_browser_net::CanPrefetchAndPrerenderIO(io_data) &&
  34          !DisableForFieldTrial();
  35 }
  36
  37 }  // namespace prefetch