chrome/browser/prerender/prerender_field_trial.cc

   1 // Copyright (c) 2012 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/prerender/prerender_field_trial.h"
   6
   7 #include <string>
   8
   9 #include "base/command_line.h"
  10 #include "base/logging.h"
  11 #include "base/metrics/field_trial.h"
  12 #include "chrome/browser/prerender/prerender_manager.h"
  13 #include "chrome/common/chrome_switches.h"
  14
  15 namespace prerender {
  16
  17 void ConfigurePrerender(const base::CommandLine& command_line) {
  18   PrerenderManager::PrerenderManagerMode mode =
  19       PrerenderManager::PRERENDER_MODE_ENABLED;
  20   if (command_line.HasSwitch(switches::kPrerenderMode)) {
  21     const std::string switch_value =
  22         command_line.GetSwitchValueASCII(switches::kPrerenderMode);
  23
  24     if (switch_value == switches::kPrerenderModeSwitchValueDisabled) {
  25       mode = PrerenderManager::PRERENDER_MODE_DISABLED;
  26     } else if (switch_value.empty() ||
  27                switch_value == switches::kPrerenderModeSwitchValueEnabled) {
  28       // The empty string means the option was provided with no value, and that
  29       // means enable.
  30       mode = PrerenderManager::PRERENDER_MODE_ENABLED;
  31     } else {
  32       mode = PrerenderManager::PRERENDER_MODE_DISABLED;
  33       LOG(ERROR) << "Invalid --prerender option received on command line: "
  34                  << switch_value;
  35       LOG(ERROR) << "Disabling prerendering!";
  36     }
  37   }
  38
  39   PrerenderManager::SetMode(mode);
  40 }
  41
  42 bool IsOmniboxEnabled(Profile* profile) {
  43   if (!profile)
  44     return false;
  45
  46   if (!PrerenderManager::IsPrerenderingPossible())
  47     return false;
  48
  49   // Override any field trial groups if the user has set a command line flag.
  50   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
  51           switches::kPrerenderFromOmnibox)) {
  52     const std::string switch_value =
  53         base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
  54             switches::kPrerenderFromOmnibox);
  55
  56     if (switch_value == switches::kPrerenderFromOmniboxSwitchValueEnabled)
  57       return true;
  58
  59     if (switch_value == switches::kPrerenderFromOmniboxSwitchValueDisabled)
  60       return false;
  61
  62     DCHECK_EQ(switches::kPrerenderFromOmniboxSwitchValueAuto, switch_value);
  63   }
  64
  65   return (base::FieldTrialList::FindFullName("PrerenderFromOmnibox") !=
  66           "OmniboxPrerenderDisabled");
  67 }
  68
  69 }  // namespace prerender