Don't repost a task on UI thread on ReceivedResponse in NavigationURLLoaderImpl

Change-Id: I0fad75959c29514e06083bffab9d05a0952d3ed3
Bug: 824840
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1728310
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Auto-Submit: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Clark DuVall <cduvall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682728}

content/browser/loader/navigation_url_loader_impl.cc

@@ -1039,8 +1039,8 @@ class NavigationURLLoaderImpl::URLLoaderRequestController
     // TODO(davidben): This copy could be avoided if ResourceResponse weren't
     // reference counted and the loader stack passed unique ownership of the
     // response. https://crbug.com/416050
-    base::PostTaskWithTraits(
-        FROM_HERE, {BrowserThread::UI},
+    RunOrPostTaskIfNecessary(
+        FROM_HERE, BrowserThread::UI,
         base::BindOnce(&NavigationURLLoaderImpl::OnReceiveResponse, owner_,
                        response->DeepCopy(),
                        std::move(url_loader_client_endpoints),