Move VariationsParamAssociator to base

base/metrics/field_trial_param_associator.cc

Index: base/metrics/field_trial_param_associator.cc
diff --git a/base/metrics/field_trial_param_associator.cc b/base/metrics/field_trial_param_associator.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b9781018fc8bc29c8bfa621f1cacb2b714e65f93
--- /dev/null
+++ b/base/metrics/field_trial_param_associator.cc
@@ -0,0 +1,51 @@
+// Copyright (c) 2016 The Chromium Authors. All rights reserved.

[Alexei Svitkine (slow), 2016/10/28 15:39:16]

No (c)

[lawrencewu, 2016/10/28 16:54:29]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/metrics/field_trial_param_associator.h"
+
+namespace base {
+
+// static
+FieldTrialParamAssociator* FieldTrialParamAssociator::GetInstance() {
+  return Singleton<FieldTrialParamAssociator,
+                   LeakySingletonTraits<FieldTrialParamAssociator>>::get();
+}
+
+bool FieldTrialParamAssociator::AssociateFieldTrialParams(
+    const std::string& trial_name,
+    const std::string& group_name,
+    const FieldTrialParams& params) {
+  AutoLock scoped_lock(lock_);
+
+  if (FieldTrialList::IsTrialActive(trial_name))
+    return false;
+
+  const FieldTrialKey key(trial_name, group_name);
+  if (ContainsKey(field_trial_params_, key))
+    return false;
+
+  field_trial_params_[key] = params;
+  return true;
+}
+
+bool FieldTrialParamAssociator::GetFieldTrialParams(
+    const std::string& trial_name,
+    FieldTrialParams* params) {
+  AutoLock scoped_lock(lock_);
+
+  const std::string group_name = FieldTrialList::FindFullName(trial_name);
+  const FieldTrialKey key(trial_name, group_name);
+  if (!ContainsKey(field_trial_params_, key))
+    return false;
+
+  *params = field_trial_params_[key];
+  return true;
+}
+
+void FieldTrialParamAssociator::ClearAllParamsForTesting() {
+  AutoLock scoped_lock(lock_);
+  field_trial_params_.clear();
+}
+
+}  // namespace base