Add Startup.TimeSinceLastStartup histogram.

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"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <set>
 #include <string>
@@ skipping 786 matching lines @@
   // doesn't know if this is the first run. This will cause some inaccuracy in
   // the UMA statistics, but this should be minor (first runs are rare).
   // TODO(bshe): Figure out which first run code to use for Aura Android. See
   // crbug.com/560498
   is_first_run = first_run::IsChromeFirstRun();
 #endif  // defined(OS_ANDROID)
 
   // Record collected startup metrics.
   startup_metric_utils::RecordBrowserMainMessageLoopStart(
       base::TimeTicks::Now(), is_first_run);
+
+  startup_metric_utils::RecordTimeSinceLastStartup(
+      g_browser_process->local_state());
 }
 
 // -----------------------------------------------------------------------------
 // TODO(viettrungluu): move more/rest of BrowserMain() into BrowserMainParts.
 
 #if defined(OS_WIN)
 #define DLLEXPORT __declspec(dllexport)
 
 // We use extern C for the prototype DLLEXPORT to avoid C++ name mangling.
 extern "C" {
@@ skipping 1093 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }