Add .SingleTab and .MultiTabs suffix to Startup.FirstWebContents.MainNavigationStart histogram.

components/startup_metric_utils/browser/startup_metric_utils.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/startup_metric_utils/browser/startup_metric_utils.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <string>
@@ skipping 702 matching lines @@
   if (WasNonBrowserUIDisplayed() || g_process_creation_ticks.Get().is_null())
     return;
 
   base::StackSamplingProfiler::SetProcessMilestone(
       metrics::CallStackProfileMetricsProvider::FIRST_NONEMPTY_PAINT);
   UMA_HISTOGRAM_AND_TRACE_WITH_TEMPERATURE_AND_SAME_VERSION_COUNT(
       UMA_HISTOGRAM_LONG_TIMES_100, "Startup.FirstWebContents.NonEmptyPaint2",
       g_process_creation_ticks.Get(), ticks);
 }
 
-void RecordFirstWebContentsMainNavigationStart(const base::TimeTicks& ticks) {
+void RecordFirstWebContentsMainNavigationStart(const base::TimeTicks& ticks,
+                                               WebContentsWorkload workload) {
   static bool is_first_call = true;
   if (!is_first_call || ticks.is_null())
     return;
   is_first_call = false;
   if (WasNonBrowserUIDisplayed() || g_process_creation_ticks.Get().is_null())
     return;
 
   base::StackSamplingProfiler::SetProcessMilestone(
       metrics::CallStackProfileMetricsProvider::MAIN_NAVIGATION_START);
   UMA_HISTOGRAM_AND_TRACE_WITH_TEMPERATURE_AND_SAME_VERSION_COUNT(
       UMA_HISTOGRAM_LONG_TIMES_100,
       "Startup.FirstWebContents.MainNavigationStart",
       g_process_creation_ticks.Get(), ticks);
+
+  // Log extra information about this startup's workload. Only added to this
+  // histogram as this extra suffix can help making it less noisy but isn't
+  // worth tripling the number of startup histograms either.
+  if (workload == WebContentsWorkload::SINGLE_TAB) {
+    UMA_HISTOGRAM_WITH_TEMPERATURE(
+        UMA_HISTOGRAM_LONG_TIMES_100,
+        "Startup.FirstWebContents.MainNavigationStart.SingleTab",
+        ticks - g_process_creation_ticks.Get());
+  } else {
+    UMA_HISTOGRAM_WITH_TEMPERATURE(
+        UMA_HISTOGRAM_LONG_TIMES_100,
+        "Startup.FirstWebContents.MainNavigationStart.MultiTabs",
+        ticks - g_process_creation_ticks.Get());
+  }
 }
 
 void RecordFirstWebContentsMainNavigationFinished(
     const base::TimeTicks& ticks) {
   static bool is_first_call = true;
   if (!is_first_call || ticks.is_null())
     return;
   is_first_call = false;
   if (WasNonBrowserUIDisplayed() || g_process_creation_ticks.Get().is_null())
     return;
 
   base::StackSamplingProfiler::SetProcessMilestone(
       metrics::CallStackProfileMetricsProvider::MAIN_NAVIGATION_FINISHED);
   UMA_HISTOGRAM_AND_TRACE_WITH_TEMPERATURE_AND_SAME_VERSION_COUNT(
       UMA_HISTOGRAM_LONG_TIMES_100,
       "Startup.FirstWebContents.MainNavigationFinished",
       g_process_creation_ticks.Get(), ticks);
 }
 
 base::TimeTicks MainEntryPointTicks() {
   return g_browser_main_entry_point_ticks.Get();
 }
 
 }  // namespace startup_metric_utils