[NTP4] Experiment for adding Chrome Web Store link to footer.

chrome/browser/ui/webui/ntp/new_tab_ui.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// 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 "build/build_config.h"
 
 #include "chrome/browser/ui/webui/ntp/new_tab_ui.h"
 
 #include <set>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/i18n/rtl.h"
 #include "base/lazy_instance.h"
 #include "base/memory/singleton.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/string_number_conversions.h"
 #include "base/threading/thread.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_types.h"
 #include "chrome/browser/sync/profile_sync_service.h"
+#include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/themes/theme_service.h"
-#include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/webui/metrics_handler.h"
 #include "chrome/browser/ui/webui/ntp/app_launcher_handler.h"
 #include "chrome/browser/ui/webui/ntp/favicon_webui_handler.h"
 #include "chrome/browser/ui/webui/ntp/foreign_session_handler.h"
 #include "chrome/browser/ui/webui/ntp/most_visited_handler.h"
 #include "chrome/browser/ui/webui/ntp/new_tab_page_handler.h"
 #include "chrome/browser/ui/webui/ntp/new_tab_page_sync_handler.h"
 #include "chrome/browser/ui/webui/ntp/ntp_login_handler.h"
+#include "chrome/browser/ui/webui/ntp/ntp_resource_cache_factory.h"
 #include "chrome/browser/ui/webui/ntp/ntp_resource_cache.h"
-#include "chrome/browser/ui/webui/ntp/ntp_resource_cache_factory.h"
 #include "chrome/browser/ui/webui/ntp/recently_closed_tabs_handler.h"
 #include "chrome/browser/ui/webui/theme_source.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
 #include "content/browser/renderer_host/render_view_host.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
@@ skipping 15 matching lines @@
 // finished.  Observed times are in the ~1200ms range on Windows.
 const int kTimeoutMs = 2000;
 
 // Strings sent to the page via jstemplates used to set the direction of the
 // HTML document based on locale.
 const char kRTLHtmlTextDirection[] = "rtl";
 const char kLTRHtmlTextDirection[] = "ltr";
 
 static base::LazyInstance<std::set<const WebUIController*> > g_live_new_tabs;
 
+// The Web Store footer experiment FieldTrial name.
+const char kWebStoreLinkExperiment[] = "WebStoreLinkExperiment";
+
 }  // namespace
 
 ///////////////////////////////////////////////////////////////////////////////
 // NewTabUI
 
 NewTabUI::NewTabUI(content::WebUI* web_ui)
     : WebUIController(web_ui) {
   g_live_new_tabs.Pointer()->insert(this);
   // Override some options on the Web UI.
   web_ui->HideFavicon();
@@ skipping 125 matching lines @@
 }
 
 // static
 void NewTabUI::RegisterUserPrefs(PrefService* prefs) {
   NewTabPageHandler::RegisterUserPrefs(prefs);
   AppLauncherHandler::RegisterUserPrefs(prefs);
   MostVisitedHandler::RegisterUserPrefs(prefs);
 }
 
 // static
+void NewTabUI::SetupFieldTrials() {
+  scoped_refptr<base::FieldTrial> trial(
+      new base::FieldTrial("WebStoreLinkExperiment", 1000, "Disabled",
+                           2012, 6, 1));
+
+  // Try to give the user a consistent experience, if possible.
+  if (base::FieldTrialList::IsOneTimeRandomizationEnabled())
+    trial->UseOneTimeRandomization();
+
+  // 4% in Enabled group.
+  trial->AppendGroup("Enabled", 40);
+}
+
+// static
+bool NewTabUI::IsWebStoreExperimentEnabled() {
+  const CommandLine* cli = CommandLine::ForCurrentProcess();
+  if (cli->HasSwitch(switches::kEnableWebStoreLink))
+    return true;
+
+  if (!base::FieldTrialList::TrialExists(kWebStoreLinkExperiment))
+    return false;
+
+  return base::FieldTrialList::FindValue(kWebStoreLinkExperiment) !=
+             base::FieldTrial::kDefaultGroupNumber;
+}
+
+// static
 void NewTabUI::SetURLTitleAndDirection(DictionaryValue* dictionary,
                                        const string16& title,
                                        const GURL& gurl) {
   dictionary->SetString("url", gurl.spec());
 
   bool using_url_as_the_title = false;
   string16 title_to_set(title);
   if (title_to_set.empty()) {
     using_url_as_the_title = true;
     title_to_set = UTF8ToUTF16(gurl.spec());
@@ skipping 60 matching lines @@
   SendResponse(request_id, html_bytes);
 }
 
 std::string NewTabUI::NewTabHTMLSource::GetMimeType(const std::string&) const {
   return "text/html";
 }
 
 bool NewTabUI::NewTabHTMLSource::ShouldReplaceExistingSource() const {
   return false;
 }