Activate prepopulated fieldtrials

chrome/common/variations/variations_util.cc

 // Copyright 2014 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/common/variations/variations_util.h"
 
 #include <string>
 #include <vector>
 
+#include "base/metrics/field_trial.h"
 #include "base/strings/string_split.h"
 #include "chrome/common/child_process_logging.h"
 #include "chrome/common/crash_keys.h"
+#include "chrome/common/variations/fieldtrial_testing_config.h"
 #include "components/variations/active_field_trials.h"
 #include "components/variations/variations_associated_data.h"
 #include "net/base/escape.h"
 
 namespace chrome_variations {
 
 namespace {
 
 std::string EscapeValue(const std::string& value) {
   return net::UnescapeURLComponent(value, net::UnescapeRule::URL_SPECIAL_CHARS);
@@ skipping 33 matching lines @@
       std::string value = EscapeValue(key_values[i + 1]);
       params[key] = value;
     }
     std::string trial = EscapeValue(group_parts[0]);
     std::string group = EscapeValue(group_parts[1]);
     variations::AssociateVariationParams(trial, group, params);
   }
   return true;
 }
 
+bool AssociateParamsFromFieldTrialConfig(
+    const FieldTrialTestingConfig& config) {
+  for (size_t i = 0; i < config.groups_size; ++i) {
+    const FieldTrialTestingGroup& group = config.groups[i];
+    if (group.params_size != 0) {
+      std::map<std::string, std::string> params;
+      for (size_t j = 0; j < group.params_size; ++j) {
+        const FieldTrialGroupParams& param = group.params[j];
+        params[param.key] = param.value;
+      }
+      variations::AssociateVariationParams(group.study, group.group_name,
+                                           params);
+    }
+    base::FieldTrialList::CreateFieldTrial(group.study, group.group_name);
+  }
+  return true;

[brettw, 2015/07/15 17:56:51]

This function never fails, but the code carefully propagates the values and
CHECKS later on. I'd just remove all of that and have it return void.

+}
+
+bool AssociateDefaultFieldTrialConfig() {
+  return AssociateParamsFromFieldTrialConfig(kFieldTrialConfig);
+}
+
 }  // namespace chrome_variations