Add more ScopedTrackers to track down jank in the RDH

in GetLoadInfoForAllRoutes.

BUG=455952

Review URL: https://codereview.chromium.org/972773002

Cr-Commit-Position: refs/heads/master@{#318773}

content/browser/loader/resource_dispatcher_host_impl.cc

@@ -2149,6 +2149,10 @@ ResourceDispatcherHostImpl::GetLoadInfoForAllRoutes() {
   // thread where they can be passed along to the respective RVHs.
   scoped_ptr<LoadInfoMap> info_map(new LoadInfoMap());
 
+  tracked_objects::ScopedTracker tracking_profile0(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "455952 ResourceDispatcherHostImpl::GetLoadInfoForAllRoutes0"));
+
   for (const auto& loader : pending_loaders_) {
     // Also poll for upload progress on this timer and send upload progress ipc
     // messages to the plugin process.
@@ -2220,6 +2224,10 @@ void ResourceDispatcherHostImpl::UpdateLoadInfo() {
   if (info_map->empty())
     return;
 
+  tracked_objects::ScopedTracker tracking_profile2(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "455952 ResourceDispatcherHostImpl::UpdateLoadInfo2"));
+
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&ResourceDispatcherHostImpl::UpdateLoadInfoOnUIThread,