Add histograms that track how long it takes to open the new tab page.

chrome/browser/browser.cc

 // Copyright (c) 2006-2009 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/browser.h"
 
 #include "app/animation.h"
 #include "app/l10n_util.h"
 #include "base/command_line.h"
 #include "base/keyboard_codes.h"
@@ skipping 1494 matching lines @@
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // Browser, TabStripModelDelegate implementation:
 
 TabContents* Browser::AddBlankTab(bool foreground) {
   return AddBlankTabAt(-1, foreground);
 }
 
 TabContents* Browser::AddBlankTabAt(int index, bool foreground) {
-  return AddTabWithURL(GURL(chrome::kChromeUINewTabURL), GURL(),
-                       PageTransition::TYPED, foreground, index, false, NULL);
+  // Time new tab page creation time.  We keep track of the timing data in
+  // TabContents, but we want to include the time it takes to create the
+  // TabContents object too.
+  base::TimeTicks new_tab_start_time = base::TimeTicks::Now();
+  TabContents* tab_contents =  AddTabWithURL(GURL(chrome::kChromeUINewTabURL),
+      GURL(), PageTransition::TYPED, foreground, index, false, NULL);
+  tab_contents->set_new_tab_start_time(new_tab_start_time);
+  return tab_contents;
 }
 
 Browser* Browser::CreateNewStripWithContents(TabContents* detached_contents,
                                              const gfx::Rect& window_bounds,
                                              const DockInfo& dock_info) {
   DCHECK(type_ == TYPE_NORMAL);
 
   gfx::Rect new_window_bounds = window_bounds;
   bool maximize = false;
   if (dock_info.GetNewWindowBounds(&new_window_bounds, &maximize))
@@ skipping 1436 matching lines @@
 ///////////////////////////////////////////////////////////////////////////////
 // BrowserToolbarModel (private):
 
 NavigationController* Browser::BrowserToolbarModel::GetNavigationController() {
   // This |current_tab| can be NULL during the initialization of the
   // toolbar during window creation (i.e. before any tabs have been added
   // to the window).
   TabContents* current_tab = browser_->GetSelectedTabContents();
   return current_tab ? &current_tab->controller() : NULL;
 }