Move prerender and prefetch logic out into chrome/browser/prerender.

This makes no logic changes.

BUG=None
TEST=None

Review URL: http://codereview.chromium.org/6596040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@76376 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 111 insertions, 82 deletions

diff --git a/chrome/browser/browser_main.cc b/chrome/browser/browser_main.cc
index feafe55..1622bfa 100644
--- a/chrome/browser/browser_main.cc
+++ b/chrome/browser/browser_main.cc
@@ -55,7 +55,7 @@
 #include "chrome/browser/prefs/browser_prefs.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/pref_value_store.h"
-#include "chrome/browser/prerender/prerender_manager.h"
+#include "chrome/browser/prerender/prerender_field_trial.h"
 #include "chrome/browser/printing/cloud_print/cloud_print_proxy_service.h"
 #include "chrome/browser/printing/print_dialog_cloud.h"
 #include "chrome/browser/process_singleton.h"
@@ -233,7 +233,7 @@ void BrowserMainParts::SetupFieldTrials() {
   ConnectionFieldTrial();
   SocketTimeoutFieldTrial();
   ProxyConnectionsFieldTrial();
-  PrefetchAndPrerenderFieldTrial();
+  prerender::ConfigurePrefetchAndPrerender(parsed_command_line());
   SpdyFieldTrial();
   ConnectBackupJobsFieldTrial();
   SSLFalseStartFieldTrial();
@@ -457,82 +457,6 @@ void BrowserMainParts::SSLFalseStartFieldTrial() {
     net::SSLConfigService::DisableFalseStart();
 }
 
-// Parse the --prerender= command line switch, which controls both prerendering
-// and prefetching.  If the switch is unset, or is set to "auto", then the user
-// is assigned to a field trial.
-void BrowserMainParts::PrefetchAndPrerenderFieldTrial() {
-  enum PrerenderOption {
-    PRERENDER_OPTION_AUTO,
-    PRERENDER_OPTION_DISABLED,
-    PRERENDER_OPTION_ENABLED,
-    PRERENDER_OPTION_PREFETCH_ONLY,
-  };
-
-  PrerenderOption prerender_option = PRERENDER_OPTION_AUTO;
-  if (parsed_command_line().HasSwitch(switches::kPrerender)) {
-    const std::string switch_value =
-        parsed_command_line().GetSwitchValueASCII(switches::kPrerender);
-
-    if (switch_value == switches::kPrerenderSwitchValueAuto) {
-      prerender_option = PRERENDER_OPTION_AUTO;
-    } else if (switch_value == switches::kPrerenderSwitchValueDisabled) {
-      prerender_option = PRERENDER_OPTION_DISABLED;
-    } else if (switch_value.empty() ||
-               switch_value == switches::kPrerenderSwitchValueEnabled) {
-      // The empty string means the option was provided with no value, and that
-      // means enable.
-      prerender_option = PRERENDER_OPTION_ENABLED;
-    } else if (switch_value == switches::kPrerenderSwitchValuePrefetchOnly) {
-      prerender_option = PRERENDER_OPTION_PREFETCH_ONLY;
-    } else {
-      prerender_option = PRERENDER_OPTION_DISABLED;
-      LOG(ERROR) << "Invalid --prerender option received on command line: "
-                 << switch_value;
-      LOG(ERROR) << "Disabling prerendering!";
-    }
-  }
-
-  switch (prerender_option) {
-    case PRERENDER_OPTION_AUTO: {
-      const base::FieldTrial::Probability kPrefetchDivisor = 1000;
-      const base::FieldTrial::Probability kYesPrefetchProbability = 500;
-      scoped_refptr<base::FieldTrial> trial(
-          new base::FieldTrial("Prefetch", kPrefetchDivisor,
-                               "ContentPrefetchDisabled", 2011, 6, 30));
-      const int kNoPrefetchGroup = trial->kDefaultGroupNumber;
-      trial->AppendGroup("ContentPrefetchEnabled", kYesPrefetchProbability);
-      const int kTrialGroup = trial->group();
-      ResourceDispatcherHost::set_is_prefetch_enabled(
-          kTrialGroup != kNoPrefetchGroup);
-
-      // There is currently no prerendering field trial.
-      prerender::PrerenderManager::SetMode(
-          prerender::PrerenderManager::PRERENDER_MODE_DISABLED);
-      break;
-    }
-    case PRERENDER_OPTION_DISABLED:
-      ResourceDispatcherHost::set_is_prefetch_enabled(false);
-      prerender::PrerenderManager::SetMode(
-          prerender::PrerenderManager::PRERENDER_MODE_DISABLED);
-      break;
-    case PRERENDER_OPTION_ENABLED:
-      ResourceDispatcherHost::set_is_prefetch_enabled(true);
-      prerender::PrerenderManager::SetMode(
-          prerender::PrerenderManager::PRERENDER_MODE_ENABLED);
-      break;
-    case PRERENDER_OPTION_PREFETCH_ONLY:
-      ResourceDispatcherHost::set_is_prefetch_enabled(true);
-      prerender::PrerenderManager::SetMode(
-          prerender::PrerenderManager::PRERENDER_MODE_DISABLED);
-      break;
-    default:
-      NOTREACHED();
-  }
-
-  UMA_HISTOGRAM_ENUMERATION("Prerender.Sessions",
-                            prerender::PrerenderManager::GetMode(),
-                            prerender::PrerenderManager::PRERENDER_MODE_MAX);
-}
 
 // If neither --enable-connect-backup-jobs or --disable-connect-backup-jobs is
 // specified, run an A/B test for automatically establishing backup TCP
diff --git a/chrome/browser/browser_main.h b/chrome/browser/browser_main.h
index 81c8c3b..96c10f1 100644
--- a/chrome/browser/browser_main.h
+++ b/chrome/browser/browser_main.h
@@ -118,10 +118,6 @@ class BrowserMainParts {
   // A/B test for spdy when --use-spdy not set.
   void SpdyFieldTrial();
 
-  // A/B test for prefetching with --(enable|disable)-prefetch not set,
-  // some histograms tracking prerender sessions.
-  void PrefetchAndPrerenderFieldTrial();
-
   // A/B test for automatically establishing a backup TCP connection when a
   // specified timeout value is reached.
   void ConnectBackupJobsFieldTrial();
diff --git a/chrome/browser/prerender/prerender_field_trial.cc b/chrome/browser/prerender/prerender_field_trial.cc
new file mode 100644
index 0000000..29e6e0a
--- /dev/null
+++ b/chrome/browser/prerender/prerender_field_trial.cc
@@ -0,0 +1,88 @@
+// Copyright (c) 2011 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_field_trial.h"
+
+#include "base/command_line.h"
+#include "base/logging.h"
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
+#include "content/browser/renderer_host/resource_dispatcher_host.h"
+#include "chrome/browser/prerender/prerender_manager.h"
+#include "chrome/common/chrome_switches.h"
+
+
+namespace prerender {
+
+void ConfigurePrefetchAndPrerender(const CommandLine& command_line) {
+  enum PrerenderOption {
+    PRERENDER_OPTION_AUTO,
+    PRERENDER_OPTION_DISABLED,
+    PRERENDER_OPTION_ENABLED,
+    PRERENDER_OPTION_PREFETCH_ONLY,
+  };
+
+  PrerenderOption prerender_option = PRERENDER_OPTION_AUTO;
+  if (command_line.HasSwitch(switches::kPrerender)) {
+    const std::string switch_value =
+        command_line.GetSwitchValueASCII(switches::kPrerender);
+
+    if (switch_value == switches::kPrerenderSwitchValueAuto) {
+      prerender_option = PRERENDER_OPTION_AUTO;
+    } else if (switch_value == switches::kPrerenderSwitchValueDisabled) {
+      prerender_option = PRERENDER_OPTION_DISABLED;
+    } else if (switch_value.empty() ||
+               switch_value == switches::kPrerenderSwitchValueEnabled) {
+      // The empty string means the option was provided with no value, and that
+      // means enable.
+      prerender_option = PRERENDER_OPTION_ENABLED;
+    } else if (switch_value == switches::kPrerenderSwitchValuePrefetchOnly) {
+      prerender_option = PRERENDER_OPTION_PREFETCH_ONLY;
+    } else {
+      prerender_option = PRERENDER_OPTION_DISABLED;
+      LOG(ERROR) << "Invalid --prerender option received on command line: "
+                 << switch_value;
+      LOG(ERROR) << "Disabling prerendering!";
+    }
+  }
+
+  switch (prerender_option) {
+    case PRERENDER_OPTION_AUTO: {
+      const base::FieldTrial::Probability kPrefetchDivisor = 1000;
+      const base::FieldTrial::Probability kYesPrefetchProbability = 500;
+      scoped_refptr<base::FieldTrial> trial(
+          new base::FieldTrial("Prefetch", kPrefetchDivisor,
+                               "ContentPrefetchDisabled", 2011, 6, 30));
+      const int kNoPrefetchGroup = trial->kDefaultGroupNumber;
+      trial->AppendGroup("ContentPrefetchEnabled", kYesPrefetchProbability);
+      const int kTrialGroup = trial->group();
+      ResourceDispatcherHost::set_is_prefetch_enabled(
+          kTrialGroup != kNoPrefetchGroup);
+
+      // There is currently no prerendering field trial.
+      PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_DISABLED);
+      break;
+    }
+    case PRERENDER_OPTION_DISABLED:
+      ResourceDispatcherHost::set_is_prefetch_enabled(false);
+      PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_DISABLED);
+      break;
+    case PRERENDER_OPTION_ENABLED:
+      ResourceDispatcherHost::set_is_prefetch_enabled(true);
+      PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_ENABLED);
+      break;
+    case PRERENDER_OPTION_PREFETCH_ONLY:
+      ResourceDispatcherHost::set_is_prefetch_enabled(true);
+      PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_DISABLED);
+      break;
+    default:
+      NOTREACHED();
+  }
+
+  UMA_HISTOGRAM_ENUMERATION("Prerender.Sessions",
+                            PrerenderManager::GetMode(),
+                            PrerenderManager::PRERENDER_MODE_MAX);
+}
+
+}  // namespace prerender
diff --git a/chrome/browser/prerender/prerender_field_trial.h b/chrome/browser/prerender/prerender_field_trial.h
new file mode 100644
index 0000000..b7543ae6
--- /dev/null
+++ b/chrome/browser/prerender/prerender_field_trial.h
@@ -0,0 +1,19 @@
+// Copyright (c) 2011 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_FIELD_TRIAL_H_
+#define CHROME_BROWSER_PRERENDER_PRERENDER_FIELD_TRIAL_H_
+
+class CommandLine;
+
+namespace prerender {
+
+// Parse the --prerender= command line switch, which controls both prerendering
+// and prefetching.  If the switch is unset, or is set to "auto", then the user
+// is assigned to a field trial.
+void ConfigurePrefetchAndPrerender(const CommandLine& command_line);
+
+}  // namespace prerender
+
+#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_FIELD_TRIAL_H_
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index a85f57d..479e052 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1601,6 +1601,8 @@
         'browser/prefs/value_map_pref_store.h',
         'browser/prerender/prerender_contents.cc',
         'browser/prerender/prerender_contents.h',
+        'browser/prerender/prerender_field_trial.cc',
+        'browser/prerender/prerender_field_trial.h',
         'browser/prerender/prerender_final_status.cc',
         'browser/prerender/prerender_final_status.h',
         'browser/prerender/prerender_manager.cc',