Do not tie cleanup tool download to SRTPromptFieldTrial field trial

chrome/browser/safe_browsing/chrome_cleaner/srt_field_trial_win.cc

 // Copyright 2015 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/safe_browsing/chrome_cleaner/srt_field_trial_win.h"
 
 #include "base/metrics/field_trial.h"
+#include "base/metrics/field_trial_params.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/string_util.h"
 #include "base/win/windows_version.h"
 #include "components/variations/variations_associated_data.h"
 #include "url/origin.h"
 
 namespace {
 
 // Field trial strings.
 const char kSRTPromptTrial[] = "SRTPromptFieldTrial";
@@ skipping 18 matching lines @@
     "https://dl.google.com/dl"
     "/softwareremovaltool/win/c/chrome_cleanup_tool.exe?chrome-prompt=1";
 
 }  // namespace
 
 namespace safe_browsing {
 
 const base::Feature kInBrowserCleanerUIFeature{
     "InBrowserCleanerUI", base::FEATURE_DISABLED_BY_DEFAULT};
 
+const base::Feature kCleanerDownloadFeature{"DownloadCleanupToolByBitness",
+                                            base::FEATURE_DISABLED_BY_DEFAULT};
+
 bool IsInSRTPromptFieldTrialGroups() {
   return !base::StartsWith(base::FieldTrialList::FindFullName(kSRTPromptTrial),
                            kSRTPromptOffGroup, base::CompareCase::SENSITIVE);
 }
 
 bool SRTPromptNeedsElevationIcon() {
   return !base::StartsWith(
       base::FieldTrialList::FindFullName(kSRTElevationTrial),
       kSRTElevationAsNeededGroup, base::CompareCase::SENSITIVE);
 }
 
 bool IsSwReporterEnabled() {
   return !base::StartsWith(
       base::FieldTrialList::FindFullName(kSRTReporterTrial),
       kSRTReporterOffGroup, base::CompareCase::SENSITIVE);
 }
 
 GURL GetLegacyDownloadURL() {
   if (base::StartsWith(base::FieldTrialList::FindFullName(kSRTPromptTrial),
                        kSRTCanaryGroup, base::CompareCase::SENSITIVE)) {
     return GURL(kCanarySRTDownloadURL);
   }
   return GURL(kMainSRTDownloadURL);
 }
 
 GURL GetSRTDownloadURL() {
   constexpr char kDownloadGroupParam[] = "download_group";
-  const std::string download_group =
-      variations::GetVariationParamValue(kSRTPromptTrial, kDownloadGroupParam);
+  const std::string download_group = base::GetFieldTrialParamValueByFeature(
+      kCleanerDownloadFeature, kDownloadGroupParam);
   if (download_group.empty())
     return GetLegacyDownloadURL();
 
   std::string architecture = base::win::OSInfo::GetInstance()->architecture() ==
                                      base::win::OSInfo::X86_ARCHITECTURE
                                  ? "x86"
                                  : "x64";
 
   // Construct download URL using the following pattern:
   // https://dl.google.com/.../win/{arch}/{group}/chrome_cleanup_tool.exe
@@ skipping 16 matching lines @@
   return variations::GetVariationParamValue(kSRTPromptTrial,
                                             kSRTPromptSeedParam);
 }
 
 void RecordSRTPromptHistogram(SRTPromptHistogramValue value) {
   UMA_HISTOGRAM_ENUMERATION("SoftwareReporter.PromptUsage", value,
                             SRT_PROMPT_MAX);
 }
 
 }  // namespace safe_browsing