[NTP4] Track the position of each app that's launched.

chrome/browser/ui/webui/ntp/app_launcher_handler.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/ui/webui/ntp/app_launcher_handler.h"
 
 #include <string>
 #include <vector>
 
 #include "base/auto_reset.h"
@@ skipping 50 matching lines @@
 extension_misc::AppLaunchBucket ParseLaunchSource(
     const std::string& launch_source) {
   int bucket_num = extension_misc::APP_LAUNCH_BUCKET_INVALID;
   base::StringToInt(launch_source, &bucket_num);
   extension_misc::AppLaunchBucket bucket =
       static_cast<extension_misc::AppLaunchBucket>(bucket_num);
   CHECK(bucket < extension_misc::APP_LAUNCH_BUCKET_BOUNDARY);
   return bucket;
 }
 
+enum {
+  APP_LAUNCHED_FROM_INDEX_WIDE_OFFSET = 100,
+  APP_LAUNCHED_FROM_INDEX_BOUNDARY = 200,
+};
+
 }  // namespace
 
 AppLauncherHandler::AppInstallInfo::AppInstallInfo() {}
 
 AppLauncherHandler::AppInstallInfo::~AppInstallInfo() {}
 
 AppLauncherHandler::AppLauncherHandler(ExtensionService* extension_service)
     : extension_service_(extension_service),
       ignore_changes_(false),
       attempted_bookmark_app_install_(false),
@@ skipping 147 matching lines @@
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("saveAppPageName",
       base::Bind(&AppLauncherHandler::HandleSaveAppPageName,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("generateAppForLink",
       base::Bind(&AppLauncherHandler::HandleGenerateAppForLink,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("recordAppLaunchByURL",
       base::Bind(&AppLauncherHandler::HandleRecordAppLaunchByURL,
                  base::Unretained(this)));
+  web_ui()->RegisterMessageCallback("recordAppLaunchedFromIndex",
+      base::Bind(&AppLauncherHandler::HandleRecordAppLaunchedFromIndex,
+                 base::Unretained(this)));
   web_ui()->RegisterMessageCallback("closeNotification",
       base::Bind(&AppLauncherHandler::HandleNotificationClose,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("setNotificationsDisabled",
       base::Bind(&AppLauncherHandler::HandleSetNotificationsDisabled,
                  base::Unretained(this)));
 }
 
 void AppLauncherHandler::Observe(int type,
                                  const content::NotificationSource& source,
@@ skipping 514 matching lines @@
   double source;
   CHECK(args->GetDouble(1, &source));
 
   extension_misc::AppLaunchBucket bucket =
       static_cast<extension_misc::AppLaunchBucket>(static_cast<int>(source));
   CHECK(source < extension_misc::APP_LAUNCH_BUCKET_BOUNDARY);
 
   RecordAppLaunchByURL(Profile::FromWebUI(web_ui()), url, bucket);
 }
 
+void AppLauncherHandler::HandleRecordAppLaunchedFromIndex(
+    const base::ListValue* args) {
+  double index_double;
+  CHECK(args->GetDouble(0, &index_double));
+  bool wide;
+  CHECK(args->GetBoolean(1, &wide));
+
+  // +1 to make it a natural (i.e. 1,2,3 instead of 0,1,2).
+  size_t index = static_cast<size_t>(index_double) + 1;
+  if (wide)
+    index += APP_LAUNCHED_FROM_INDEX_WIDE_OFFSET;
+  else if (index >= APP_LAUNCHED_FROM_INDEX_WIDE_OFFSET + 1)
+    index = APP_LAUNCHED_FROM_INDEX_BOUNDARY + 1;
+
+  UMA_HISTOGRAM_ENUMERATION("NewTabPage.AppLaunchedFromIndex", index,
+                            APP_LAUNCHED_FROM_INDEX_BOUNDARY);
+}
+
 void AppLauncherHandler::HandleNotificationClose(const ListValue* args) {
   std::string extension_id;
   CHECK(args->GetString(0, &extension_id));
 
   const Extension* extension = extension_service_->GetExtensionById(
       extension_id, true);
   if (!extension)
     return;
 
   UMA_HISTOGRAM_COUNTS("AppNotification.NTPNotificationClosed", 1);
@@ skipping 213 matching lines @@
 
 void AppLauncherHandler::UninstallDefaultApps() {
   AppsPromo* apps_promo = extension_service_->apps_promo();
   const ExtensionIdSet& app_ids = apps_promo->old_default_apps();
   for (ExtensionIdSet::const_iterator iter = app_ids.begin();
        iter != app_ids.end(); ++iter) {
     if (extension_service_->GetExtensionById(*iter, true))
       extension_service_->UninstallExtension(*iter, false, NULL);
   }
 }