Add CurrentProcessInfo::CreationTime() for Linux

chrome/browser/ui/browser.cc

 // Copyright 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/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // defined(OS_WIN)
@@ skipping 1193 matching lines @@
 
 bool Browser::IsMouseLocked() const {
   return fullscreen_controller_->IsMouseLocked();
 }
 
 void Browser::OnWindowDidShow() {
   if (window_has_shown_)
     return;
   window_has_shown_ = true;
 
-// CurrentProcessInfo::CreationTime() is currently only implemented on Mac and
-// Windows.
-#if defined(OS_MACOSX) || defined(OS_WIN)
+// CurrentProcessInfo::CreationTime() is missing on some platforms.
+#if defined(OS_MACOSX) || defined(OS_WIN) || defined(OS_LINUX)
   // Measure the latency from startup till the first browser window becomes
   // visible.
   static bool is_first_browser_window = true;
   if (is_first_browser_window &&
       !startup_metric_utils::WasNonBrowserUIDisplayed()) {
     is_first_browser_window = false;
-    const base::Time* process_creation_time =
+    const base::Time process_creation_time =
         base::CurrentProcessInfo::CreationTime();
 
-    if (process_creation_time) {
+    if (!process_creation_time.is_null()) {
       UMA_HISTOGRAM_LONG_TIMES(
           "Startup.BrowserWindowDisplay",
-          base::Time::Now() - *process_creation_time);
+          base::Time::Now() - process_creation_time);
     }
   }
-#endif  // defined(OS_MACOSX) || defined(OS_WIN)
+#endif  // defined(OS_MACOSX) || defined(OS_WIN) || defined(OS_LINUX)
 
   // Nothing to do for non-tabbed windows.
   if (!is_type_tabbed())
     return;
 
   // Show any pending global error bubble.
   GlobalErrorService* service =
       GlobalErrorServiceFactory::GetForProfile(profile());
   GlobalError* error = service->GetFirstGlobalErrorWithBubbleView();
   if (error)
@@ skipping 1004 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }