Add "SessionRestore.ForegroundTabFirstPaint2" histogram.

chrome/browser/sessions/session_restore.cc

Index: chrome/browser/sessions/session_restore.cc
diff --git a/chrome/browser/sessions/session_restore.cc b/chrome/browser/sessions/session_restore.cc
index 83b71f4e94be868960976a944364dbdb4f5f8c26..090d5f32898676d4d190f73bf96b625117d93a41 100644
--- a/chrome/browser/sessions/session_restore.cc
+++ b/chrome/browser/sessions/session_restore.cc
@@ -432,6 +432,23 @@ void TabLoader::Observe(int type,
                   100,
                   base::Histogram::kUmaTargetedHistogramFlag);
           counter_for_count->AddTime(time_to_paint);
+          UMA_HISTOGRAM_CUSTOM_TIMES("SessionRestore.ForegroundTabFirstPaint2",
+                                     time_to_paint,
+                                     base::TimeDelta::FromMilliseconds(100),
+                                     base::TimeDelta::FromMinutes(16),
+                                     50);
+          // Record a time for the number of tabs, to help track down
+          // contention.
+          time_for_count = base::StringPrintf(
+              "SessionRestore.ForegroundTabFirstPaint2_%d", tab_count_);

[Alexei Svitkine (slow), 2015/03/16 19:32:11]

Please update histogram_suffixes element SessionRestoreTabCounts to include the
new histogram name.

[danduong, 2015/03/16 20:42:39]

Done.

+          counter_for_count =
+              base::Histogram::FactoryTimeGet(
+                  time_for_count,
+                  base::TimeDelta::FromMilliseconds(100),
+                  base::TimeDelta::FromMinutes(16),
+                  50,
+                  base::Histogram::kUmaTargetedHistogramFlag);
+          counter_for_count->AddTime(time_to_paint);
         } else if (render_widget_hosts_loading_.find(render_widget_host) ==
             render_widget_hosts_loading_.end()) {
           // If this is a host for a tab we're not loading some other tab