Supporting study definitions without default groups and end_date filtering.

components/variations/proto/study.proto

 // 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.
 
 syntax = "proto2";
 
 option optimize_for = LITE_RUNTIME;
 
 package variations;
 
 // This defines the Protocol Buffer representation of a Chrome Variations study
 // as sent to clients of the Variations server.
 //
 // Next tag: 13
 message Study {
   // The name of the study. Should not contain spaces or special characters.
   // Ex: "my_study"
   required string name = 1;
 
+  // DEPRECATED: Prefer end_date instead.
   // The expiry date of the study in Unix time format. (Seconds since midnight
   // January 1, 1970 UTC). See: http://en.wikipedia.org/wiki/Unix_time
   //
   // A study that has expired will be disabled, and users will be assigned
   // groups based on the default_experiment_name. This will take precedence over
   // a corresponding hardcoded field trial in the client.
   //
   // Ex: 1330893974  (corresponds to 2012-03-04 20:46:14Z)
   optional int64 expiry_date = 3;
 
   // Consistency setting for a study.
   enum Consistency {
     SESSION = 0;  // Can't change within a session.
     PERMANENT = 1;  // Can't change for a given user.
   }
 
   // Consistency setting for this study. Optional - defaults to SESSION.
   // Ex: PERMANENT
   optional Consistency consistency = 7 [default = SESSION];
 
   // Name of the experiment that gets the default experience. This experiment
-  // must be included in the list below.
+  // must be included in the list below. If not specified, a dummy experiment
+  // named "variations_dummy_default" is used, and will have a probability

[rkaplow, 2017/01/04 15:58:25]

this isn't the name you put above

[jwd, 2017/01/04 21:10:22]

Done.

+  // weight of 0.
   // Ex: "default"
   optional string default_experiment_name = 8;
 
   // An experiment within the study.
   //
   // Next tag: 14
   message Experiment {
     // A named parameter value for this experiment.
     //
     // Next tag: 3
@@ skipping 139 matching lines @@
   // Possible form factors Chrome is running on.
   enum FormFactor {
     DESKTOP = 0;
     PHONE   = 1;
     TABLET  = 2;
   }
 
   // Filtering criteria specifying whether this study is applicable to a given
   // Chrome instance.
   //
-  // Next tag: 13
+  // Next tag: 14
   message Filter {
     // The start date of the study in Unix time format. (Seconds since midnight
     // January 1, 1970 UTC). See: http://en.wikipedia.org/wiki/Unix_time
     // Ex: 1330893974  (corresponds to 2012-03-04 20:46:14Z)
     optional int64 start_date = 1;
 
+    // The end date of the study in Unix time format. (Seconds since midnight
+    // January 1, 1970 UTC). See: http://en.wikipedia.org/wiki/Unix_time
+    // Ex: 1330893974  (corresponds to 2012-03-04 20:46:14Z)
+    // Mutually exclusive with expiry_date. The difference between end_date and
+    // expiry_date is that, when end_date is past, the field trial will not be
+    // created. When expiry_date is past, the trial is still created, but will
+    // be disabled, casing it to select it's default group.
+    optional int64 end_date = 13;
+
     // The minimum Chrome version for this study, allowing a trailing '*'
     // character for pattern matching. Inclusive. (To check for a match, iterate
     // over each component checking >= until a * or end of string is reached.)
     // Optional - if not specified, there is no minimum version.
     // Ex: "17.0.963.46", "17.0.963.*", "17.*"
     optional string min_version = 2;
 
     // The maximum Chrome version for this study; same formatting as
     // |min_version| above. Inclusive. (To check for a match, iterate over each
     // component checking <= until a * or end of string is reached.)
@@ skipping 75 matching lines @@
     // This is recommended for most studies that include client code.
     ACTIVATION_EXPLICIT  = 0;
     // The study will be automatically activated when it is created. This
     // is recommended for studies that do not have any client logic.
     ACTIVATION_AUTO      = 1;
   }
 
   // Activation type for this study. Defaults to ACTIVATION_EXPLICIT if omitted.
   optional ActivationType activation_type = 12;
 }