Add a private API method metricsPrivate.getFieldTrial(), which returns

chrome/browser/extensions/api/metrics_private/metrics_private_api.cc

 // 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.
 
 #include "chrome/browser/extensions/api/metrics_private/metrics_private_api.h"
 
 #include <algorithm>
 
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/common/extensions/api/metrics_private.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/user_metrics.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/settings/cros_settings.h"
 #endif  // OS_CHROMEOS
 
 namespace extensions {
 
 namespace GetIsCrashReportingEnabled =
     api::metrics_private::GetIsCrashReportingEnabled;
+namespace GetFieldTrial = api::metrics_private::GetFieldTrial;
 namespace RecordUserAction = api::metrics_private::RecordUserAction;
 namespace RecordValue = api::metrics_private::RecordValue;
 namespace RecordPercentage = api::metrics_private::RecordPercentage;
 namespace RecordCount = api::metrics_private::RecordCount;
 namespace RecordSmallCount = api::metrics_private::RecordSmallCount;
 namespace RecordMediumCount = api::metrics_private::RecordMediumCount;
 namespace RecordTime = api::metrics_private::RecordTime;
 namespace RecordMediumTime = api::metrics_private::RecordMediumTime;
 namespace RecordLongTime = api::metrics_private::RecordLongTime;
 
@@ skipping 24 matching lines @@
 #else
   return false;
 #endif
 }
 
 bool MetricsPrivateGetIsCrashReportingEnabledFunction::RunImpl() {
   SetResult(new base::FundamentalValue(IsCrashReportingEnabled()));
   return true;
 }
 
+bool MetricsPrivateGetFieldTrialFunction::RunImpl() {
+  std::string name;
+  EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &name));
+
+  SetResult(new base::StringValue(base::FieldTrialList::FindFullName(name)));
+  return true;
+}
+
 bool MetricsPrivateRecordUserActionFunction::RunImpl() {
   scoped_ptr<RecordUserAction::Params> params(
       RecordUserAction::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
 
   content::RecordComputedAction(params->name);
   return true;
 }
 
 bool MetricsHistogramHelperFunction::GetNameAndSample(std::string* name,
@@ skipping 102 matching lines @@
 bool MetricsPrivateRecordLongTimeFunction::RunImpl() {
   scoped_ptr<RecordLongTime::Params> params(
       RecordLongTime::Params::Create(*args_));
   EXTENSION_FUNCTION_VALIDATE(params.get());
   static const int kOneHourMs = 60 * 60 * 1000;
   return RecordValue(params->metric_name, base::HISTOGRAM,
                      1, kOneHourMs, 50, params->value);
 }
 
 } // namespace extensions