Add more instrumentation to track down jank.

chrome/browser/net/proxy_service_factory.cc

Index: chrome/browser/net/proxy_service_factory.cc
diff --git a/chrome/browser/net/proxy_service_factory.cc b/chrome/browser/net/proxy_service_factory.cc
index 87c1f290b30e677f4c7f983aa9f0e4d0ef6182bd..bfc6a828c326b8840c83eaac5473e12c71add095 100644
--- a/chrome/browser/net/proxy_service_factory.cc
+++ b/chrome/browser/net/proxy_service_factory.cc
@@ -122,6 +122,11 @@ net::ProxyService* ProxyServiceFactory::CreateProxyService(
     }
   }
 
+  // TODO(eroman): Remove once crbug.com/454983 is fixed.
+  tracked_objects::ScopedTracker tracking_profile2(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "454983 ProxyServiceFactory::CreateProxyService_2"));
+
   net::ProxyService* proxy_service = NULL;
   if (use_v8) {
 #if defined(OS_IOS)
@@ -132,10 +137,20 @@ net::ProxyService* ProxyServiceFactory::CreateProxyService(
     dhcp_proxy_script_fetcher =
         new chromeos::DhcpProxyScriptFetcherChromeos(context);
 #else
+    // TODO(eroman): Remove once crbug.com/454983 is fixed.
+    tracked_objects::ScopedTracker tracking_profile3(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "454983 ProxyServiceFactory::CreateProxyService_3"));

[mmenke, 2015/03/06 22:56:44]

optional nit:  Should this be just before the #ifdefined?  Even if we don't care
about ChromeOS, seems a little weird here.

Actually, there's so little between the start of "if (use_v8)" and this, seems
like this makes the most sense just after the if.

[eroman, 2015/03/06 23:02:43]

Done.

+
     net::DhcpProxyScriptFetcherFactory dhcp_factory;
     dhcp_proxy_script_fetcher = dhcp_factory.Create(context);
 #endif
 
+    // TODO(eroman): Remove once crbug.com/454983 is fixed.
+    tracked_objects::ScopedTracker tracking_profile3(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "454983 ProxyServiceFactory::CreateProxyService_3"));
+
     proxy_service = net::CreateProxyServiceUsingV8ProxyResolver(
         proxy_config_service,
         new net::ProxyScriptFetcherImpl(context),
@@ -145,6 +160,11 @@ net::ProxyService* ProxyServiceFactory::CreateProxyService(
         network_delegate);
 #endif  // defined(OS_IOS)
   } else {
+    // TODO(eroman): Remove once crbug.com/454983 is fixed.
+    tracked_objects::ScopedTracker tracking_profile4(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "454983 ProxyServiceFactory::CreateProxyService_4"));
+
     proxy_service = net::ProxyService::CreateUsingSystemProxyResolver(
         proxy_config_service,
         num_pac_threads,