Remove all remaining traces of MessageLoopProxy.

chrome/browser/engagement/site_engagement_service.cc

Index: chrome/browser/engagement/site_engagement_service.cc
diff --git a/chrome/browser/engagement/site_engagement_service.cc b/chrome/browser/engagement/site_engagement_service.cc
index 5bb379ed311b396317220ec993b6ce75c0307d88..56ca99d6bde5116b56d979f2d7fae873aa4edc40 100644
--- a/chrome/browser/engagement/site_engagement_service.cc
+++ b/chrome/browser/engagement/site_engagement_service.cc
@@ -109,7 +109,7 @@ bool SiteEngagementService::IsEnabled() {
 SiteEngagementService::SiteEngagementService(Profile* profile)
     : SiteEngagementService(profile, base::WrapUnique(new base::DefaultClock)) {
   content::BrowserThread::PostAfterStartupTask(
-      FROM_HERE, content::BrowserThread::GetMessageLoopProxyForThread(
+      FROM_HERE, content::BrowserThread::GetTaskRunnerForThread(
                      content::BrowserThread::UI),
       base::Bind(&SiteEngagementService::AfterStartupTask,
                  weak_factory_.GetWeakPtr()));