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

chrome/browser/web_resource/web_resource_service.h

Index: chrome/browser/web_resource/web_resource_service.h
===================================================================
--- chrome/browser/web_resource/web_resource_service.h	(revision 72151)
+++ chrome/browser/web_resource/web_resource_service.h	(working copy)
@@ -65,7 +65,7 @@
   //       {
   //         "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",
@@ -84,6 +84,18 @@
   //   }
   // }
   //
+  // 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);