mac: Add a profiler for startup time.

components/startup_metric_utils/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_STARTUP_METRIC_UTILS_H_
 #define COMPONENTS_STARTUP_METRIC_UTILS_STARTUP_METRIC_UTILS_H_
 
 #include <string>
 
 #include "base/time/time.h"
@@ skipping 34 matching lines @@
 
 // Called just before the message loop is about to start. Entry point to record
 // startup stats.
 // |is_first_run| - is the current launch part of a first run.
 void OnBrowserStartupComplete(bool is_first_run);
 
 // Called when the initial page load has finished in order to record startup
 // stats.
 void OnInitialPageLoadComplete();
 
+// Returns the time of main entry recorded from RecordMainEntryPointTime.
+// Returns NULL if that method has not yet been called.
+// This method is expected to be called from the UI thread.
+const base::Time* MainEntryPointTime();
+
 // Scoper that records the time period before it's destructed in a histogram
 // with the given name. The histogram is only recorded for slow chrome startups.
 // Useful for trying to figure out what parts of Chrome cause slow startup.
 class ScopedSlowStartupUMA {
  public:
   explicit ScopedSlowStartupUMA(const std::string& histogram_name)
       : start_time_(base::TimeTicks::Now()),
         histogram_name_(histogram_name) {}
 
   ~ScopedSlowStartupUMA();
 
  private:
   const base::TimeTicks start_time_;
   const std::string histogram_name_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedSlowStartupUMA);
 };
 
 }  // namespace startup_metric_utils
 
 #endif  // COMPONENTS_STARTUP_METRIC_UTILS_STARTUP_METRIC_UTILS_H_