Add a mechanism to force parameters of a group to a specific value.

components/variations/variations_associated_data_unittest.cc

 // Copyright 2013 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 "components/variations/variations_associated_data.h"
 
 #include "base/metrics/field_trial.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace variations {
@@ skipping 338 matching lines @@
   ASSERT_FALSE(IsFieldTrialActive(kTrialName));
   scoped_refptr<base::FieldTrial> trial(
       CreateFieldTrial(kTrialName, 100, "A", NULL));
   ASSERT_FALSE(IsFieldTrialActive(kTrialName));
 
   std::map<std::string, std::string> params;
   EXPECT_EQ(std::string(), GetVariationParamValue(kTrialName, "x"));
   ASSERT_TRUE(IsFieldTrialActive(kTrialName));
 }
 
+TEST_F(VariationsAssociatedDataTest, AssociateParamsFromString) {
+  const std::string kTrialName = "AssociateVariationParams";
+  const std::string kVariationsString =
+      "AssociateVariationParams.A:a/10/b/test,AssociateVariationParams.B:a/%2F";
+  ASSERT_TRUE(AssociateParamsFromString(kVariationsString));
+
+  base::FieldTrialList::CreateFieldTrial(kTrialName, "B");
+  EXPECT_EQ("/", GetVariationParamValue(kTrialName, "a"));
+  EXPECT_EQ(std::string(), GetVariationParamValue(kTrialName, "b"));
+  EXPECT_EQ(std::string(), GetVariationParamValue(kTrialName, "x"));
+
+  std::map<std::string, std::string> params;
+  EXPECT_TRUE(GetVariationParams(kTrialName, &params));
+  EXPECT_EQ(1U, params.size());
+  EXPECT_EQ("/", params["a"]);
+}
+
 }  // namespace variations