Add possibility to divide chrome users into groups of equal size, and change ...

chrome/browser/web_resource/web_resource_service.h

 // Copyright (c) 2010 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_WEB_RESOURCE_WEB_RESOURCE_SERVICE_H_
 #define CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_SERVICE_H_
 #pragma once
 
 #include <string>
 
 #include "base/file_path.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/utility_process_host.h"
 #include "chrome/common/web_resource/web_resource_unpacker.h"
 
 class Profile;
 
 namespace WebResourceServiceUtil {
 
 // Certain promotions should only be shown to certain classes of users. This
 // function will change to reflect each kind of promotion.
 bool CanShowPromo(Profile* profile);
 
 }  // namespace WebResourceService
 
+// A WebResourceService fetches data from a web resource server to be used to
+// dynamically change the appearance of the New Tab Page. For example, it has
+// been used to fetch "tips" to be displayed on the NTP, or to display
+// promotional messages to certain groups of Chrome users.
+//
+// TODO(mirandac): Arrange for a server to be set up specifically for promo
+// messages, which have until now been piggybacked onto the old tips server
+// structure. (see http://crbug.com/70634 for details.)
 class WebResourceService
     : public UtilityProcessHost::Client {
  public:
   explicit WebResourceService(Profile* profile);
 
   // Sleep until cache needs to be updated, but always for at least 5 seconds
   // so we don't interfere with startup.  Then begin updating resources.
   void StartAfterDelay();
 
   // We have successfully pulled data from a resource server; now launch
@@ skipping 22 matching lines @@
 
   // Unpack the web resource as a custom promo signal. Expects a start and end
   // signal, with the promo to be shown in the tooltip of the start signal
   // field. Delivery will be in json in the form of:
   // {
   //   "topic": {
   //     "answers": [
   //       {
   //         "answer_id": "1067976",
   //         "name": "promo_start",
-  //         "question": "",
+  //         "question": "1:24",
   //         "tooltip":
   //       "Click \u003ca href=http://www.google.com\u003ehere\u003c/a\u003e!",
   //         "inproduct": "10/8/09 12:00",
   //         "inproduct_target": null
   //       },
   //       {
   //         "answer_id": "1067976",
   //         "name": "promo_end",
   //         "question": "",
   //         "tooltip": "",
   //         "inproduct": "10/8/11 12:00",
   //         "inproduct_target": null
   //       },
   //       ...
   //     ]
   //   }
   // }
   //
+  // Because the promo signal data is piggybacked onto the tip server, the
+  // values don't exactly correspond with the field names:
+  //
+  // For "promo_start" or "promo_end", the date to start or stop showing the
+  // promotional line is given by the "inproduct" line.
+  // For "promo_start", the promotional line itself is given in the "tooltip"
+  // field. The "question" field gives the type of builds that should be shown
+  // this promo (see the BuildType enum in web_resource_service.cc) and the
+  // number of hours that each promo group should see it, separated by ":".
+  // For example, "7:24" would indicate that all builds should see the promo,
+  // and each group should see it for 24 hours.
+  //
   // Public for unit testing.
   void UnpackPromoSignal(const DictionaryValue& parsed_json);
 
   // Unpack the web resource as a custom logo signal. Expects a start and end
   // signal. Delivery will be in json in the form of:
   // {
   //   "topic": {
   //     "answers": [
   //       {
   //         "answer_id": "107366",
@@ skipping 81 matching lines @@
   int cache_update_delay_;
 
   // True if a task has been set to update the cache when a new web resource
   // becomes available.
   bool web_resource_update_scheduled_;
 
   DISALLOW_COPY_AND_ASSIGN(WebResourceService);
 };
 
 #endif  // CHROME_BROWSER_WEB_RESOURCE_WEB_RESOURCE_SERVICE_H_