[Cleanup] Migrate the WatcherMetricsProvider to use the Task Scheduler.

chrome/browser/metrics/chrome_metrics_service_client.cc

Index: chrome/browser/metrics/chrome_metrics_service_client.cc
diff --git a/chrome/browser/metrics/chrome_metrics_service_client.cc b/chrome/browser/metrics/chrome_metrics_service_client.cc
index 721b052dcd85c83fbe18cda9b188f57584a82080..8f7da5509790c85642695eece93b630b48d4b561 100644
--- a/chrome/browser/metrics/chrome_metrics_service_client.cc
+++ b/chrome/browser/metrics/chrome_metrics_service_client.cc
@@ -695,8 +695,7 @@ void ChromeMetricsServiceClient::RegisterMetricsServiceProviders() {
   }
   watcher_metrics_provider_ = new browser_watcher::WatcherMetricsProviderWin(
       chrome::GetBrowserExitCodesRegistryPath(), user_data_dir, crash_dir,
-      base::Bind(&GetExecutableVersionDetails),
-      content::BrowserThread::GetBlockingPool());
+      base::Bind(&GetExecutableVersionDetails));
   metrics_service_->RegisterMetricsProvider(
       std::unique_ptr<metrics::MetricsProvider>(watcher_metrics_provider_));