Clean Read/SetExperimentLabels to remove check for Chrome build.

chrome/browser/metrics/variations/chrome_variations_service_client.cc

Index: chrome/browser/metrics/variations/chrome_variations_service_client.cc
diff --git a/chrome/browser/metrics/variations/chrome_variations_service_client.cc b/chrome/browser/metrics/variations/chrome_variations_service_client.cc
index e4bfb1e89c3aedc9b374a40c625959247eec29a5..bbddc722b329607d67fb2f173f994f757c64bb79 100644
--- a/chrome/browser/metrics/variations/chrome_variations_service_client.cc
+++ b/chrome/browser/metrics/variations/chrome_variations_service_client.cc
@@ -46,46 +46,6 @@ base::Version GetVersionForSimulation() {
   return base::Version(version_info::GetVersionNumber());
 }
 
-#if defined(OS_WIN)
-// Clear all Variations experiment labels from Google Update Registry Labels.
-// TODO(jwd): Remove this once we're confident most clients no longer have these
-// labels (M57-M58 timeframe).
-void ClearGoogleUpdateRegistryLabels() {
-  base::ThreadRestrictions::AssertIOAllowed();
-
-  // Note that all registry operations are done here on the UI thread as there
-  // are no threading restrictions on them.
-  const bool is_system_install = !InstallUtil::IsPerUserInstall();
-
-  // Read the current bits from the registry.
-  base::string16 registry_labels;
-  bool success = GoogleUpdateSettings::ReadExperimentLabels(is_system_install,
-                                                            &registry_labels);
-
-  if (!success) {
-    DVLOG(1) << "Error reading Variation labels from the registry.";
-    return;
-  }
-
-  // Only keep the non-Variations contents of experiment_labels.
-  const base::string16 labels_to_keep =
-      variations::ExtractNonVariationLabels(registry_labels);
-
-  // This is a weak check, which can give false positives if the implementation
-  // of variations::ExtractNonVariationLabels changes, but should be fine for
-  // temporary code.
-  bool needs_clearing = labels_to_keep != registry_labels;
-
-  UMA_HISTOGRAM_BOOLEAN("Variations.GoogleUpdateRegistryLabelsNeedClearing",
-                        needs_clearing);
-
-  if (!needs_clearing)
-    return;
-
-  GoogleUpdateSettings::SetExperimentLabels(is_system_install, labels_to_keep);
-}
-#endif  // defined(OS_WIN)
-
 }  // namespace
 
 ChromeVariationsServiceClient::ChromeVariationsServiceClient() {}
@@ -129,15 +89,3 @@ bool ChromeVariationsServiceClient::OverridesRestrictParameter(
   return false;
 #endif
 }
-
-void ChromeVariationsServiceClient::OnInitialStartup() {
-#if defined(OS_WIN)
-  // TODO(jwd): Remove this once we're confident most clients no longer have
-  // these labels (M57-M58 timeframe).
-  // Do the work on a blocking pool thread, as chrome://profiler has shown that
-  // it can cause jank if done on the UI thrread.
-  content::BrowserThread::GetBlockingPool()->PostDelayedTask(
-      FROM_HERE, base::Bind(&ClearGoogleUpdateRegistryLabels),
-      base::TimeDelta::FromSeconds(5));
-#endif
-}