Record first run startup metrics.

chrome/browser/chrome_browser_main.cc

 // Copyright (c) 2012 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 "chrome/browser/chrome_browser_main.h"
 
 #if defined(TOOLKIT_GTK)
 #include <gtk/gtk.h>
 #endif
 
@@ skipping 1605 matching lines @@
   return true;
 #else
   // Set the result code set in PreMainMessageLoopRun or set above.
   *result_code = result_code_;
   if (!run_message_loop_)
     return true;  // Don't run the default message loop.
 
   // These should be invoked as close to the start of the browser's
   // UI thread message loop as possible to get a stable measurement
   // across versions.
-  RecordBrowserStartupTime();
+  RecordBrowserStartupTime(do_first_run_tasks_);
   startup_timer_->SignalStartupComplete(
       performance_monitor::StartupTimer::STARTUP_NORMAL);
 
   DCHECK_EQ(MessageLoop::TYPE_UI, MessageLoop::current()->type());
 #if !defined(USE_AURA) && defined(TOOLKIT_VIEWS)
   views::AcceleratorHandler accelerator_handler;
   base::RunLoop run_loop(&accelerator_handler);
 #else
   base::RunLoop run_loop;
 #endif
@@ skipping 100 matching lines @@
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }
 
 // Misc ------------------------------------------------------------------------
 
-void RecordBrowserStartupTime() {
+void RecordBrowserStartupTime(bool is_first_run) {
   // Don't record any metrics if UI was displayed before this point e.g.
   // warning dialogs.
   if (startup_metric_utils::WasNonBrowserUIDisplayed())
     return;
 
 // CurrentProcessInfo::CreationTime() is currently only implemented on Mac and
 // Windows.
 #if defined(OS_MACOSX) || defined(OS_WIN)
   const base::Time* process_creation_time =
       base::CurrentProcessInfo::CreationTime();
 
-  if (process_creation_time)
-    RecordPreReadExperimentTime("Startup.BrowserMessageLoopStartTime",
+  if (process_creation_time) {
+    RecordPreReadExperimentTime(
+        is_first_run ? "Startup.FirstRun.BrowserMessageLoopStartTime" :
+                       "Startup.BrowserMessageLoopStartTime",

[jeremy, 2013/05/05 12:35:56]

I don't think you need to add a new histogram here, add one to the
"Startup.BrowserMessageLoopStartTimeFromMainEntry" instead.

LoopStartTime and LoopStartTimeFromMainEntry basically measure the same thing
(the former being the old version which is more noisy since it measures from the
OS' notion of process startup so we also measure binary load time)

[gab, 2013/05/06 16:19:54]

Ok, let's not record this one on first run though then since that would add even
more noise to this stat.

         base::Time::Now() - *process_creation_time);
+  }
 #endif  // defined(OS_MACOSX) || defined(OS_WIN)
 
   // Record collected startup metrics.
-  startup_metric_utils::OnBrowserStartupComplete();
+  startup_metric_utils::OnBrowserStartupComplete(is_first_run);
 
   // Deletes self.
   new LoadCompleteListener();
 }
 
 // This code is specific to the Windows-only PreReadExperiment field-trial.
 void RecordPreReadExperimentTime(const char* name, base::TimeDelta time) {
   DCHECK(name != NULL);
 
   // This gets called with different histogram names, so we don't want to use
@@ skipping 17 matching lines @@
     if (base::win::GetVersion() <= base::win::VERSION_XP)
       uma_name += "_XP";
 
     uma_name += "_PreRead_";
     uma_name += pre_read_percentage;
     AddPreReadHistogramTime(uma_name.c_str(), time);
   }
 #endif
 #endif
 }