Extend VariationParamsManager to support feature associations.

components/variations/BUILD.gn

 # 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.
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 static_library("variations") {
   sources = [
@@ skipping 86 matching lines @@
   sources = [
     "active_field_trials_unittest.cc",
     "caching_permuted_entropy_provider_unittest.cc",
     "entropy_provider_unittest.cc",
     "experiment_labels_unittest.cc",
     "metrics_util_unittest.cc",
     "net/variations_http_headers_unittest.cc",
     "study_filtering_unittest.cc",
     "variations_associated_data_unittest.cc",
     "variations_http_header_provider_unittest.cc",
+    "variations_params_manager.cc",
+    "variations_params_manager.h",
     "variations_request_scheduler_unittest.cc",
     "variations_seed_processor_unittest.cc",
     "variations_seed_simulator_unittest.cc",
     "variations_seed_store_unittest.cc",
   ]
 
   if (is_android || is_ios) {
     sources += [ "variations_request_scheduler_mobile_unittest.cc" ]
   }
 
   deps = [
     ":variations",
     "net",
     "proto",
     "//base/test:test_support",
     "//components/prefs:test_support",
     "//testing/gtest",
     "//third_party/zlib:compression_utils",
   ]
 }