Add UMA metric: Startup.BrowserMainToRendererMain.

components/startup_metric_utils/browser/startup_metric_utils.h

 // 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.
 
 #ifndef COMPONENTS_STARTUP_METRIC_UTILS_BROWSER_STARTUP_METRIC_UTILS_H_
 #define COMPONENTS_STARTUP_METRIC_UTILS_BROWSER_STARTUP_METRIC_UTILS_H_
 
 #include <string>
 
 #include "base/time/time.h"
@@ skipping 54 matching lines @@
 // |is_first_run| - is the current launch part of a first run.
 void RecordBrowserMainMessageLoopStart(const base::TimeTicks& ticks,
                                        bool is_first_run);
 
 // Call this with the time when the first browser window became visible.
 void RecordBrowserWindowDisplay(const base::TimeTicks& ticks);
 
 // Call this with the time delta that the browser spent opening its tabs.
 void RecordBrowserOpenTabsDelta(const base::TimeDelta& delta);
 
+// Call this with a renderer main entry time. The value provided for the first
+// call to this function is used to compute
+// Startup.LoadTime.BrowserMainToRendererMain. Further calls to this
+// function are ignored.
+void RecordRendererMainEntryTime(const base::TimeTicks& ticks);
+
 // Call this with the time when the first web contents loaded its main frame,
 // only if the first web contents was unimpended in its attempt to do so.
 void RecordFirstWebContentsMainFrameLoad(const base::TimeTicks& ticks);
 
 // Call this with the time when the first web contents loaded its main frame.
 // This records an old stat kept for comparison purposes until M49.
 void RecordDeprecatedFirstWebContentsMainFrameLoad(
     const base::TimeTicks& ticks);
 
 // Call this with the time when the first web contents had a non-empty paint,
@@ skipping 19 matching lines @@
 base::TimeTicks MainEntryPointTicks();
 
 // Returns the startup type. This is only currently supported on the Windows
 // platform and will simply return UNCERTAIN_STARTUP_TYPE on other platforms.
 // This is only valid after a call to RecordBrowserMainMessageLoopStart().
 StartupTemperature GetStartupTemperature();
 
 }  // namespace startup_metric_utils
 
 #endif  // COMPONENTS_STARTUP_METRIC_UTILS_BROWSER_STARTUP_METRIC_UTILS_H_