Prerendered pages are swapped in at browser::Navigate time.

chrome/browser/ui/browser_navigator.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/ui/browser_navigator.h"
 
 #include <algorithm>
 
 #include "base/command_line.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_about_handler.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_tab_helper.h"
 #include "chrome/browser/google/google_url_tracker.h"
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/prefs/incognito_mode_prefs.h"
 #include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prerender/prerender_manager.h"
+#include "chrome/browser/prerender/prerender_manager_factory.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/rlz/rlz.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/omnibox/location_bar.h"
 #include "chrome/browser/ui/status_bubble.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
@@ skipping 325 matching lines @@
                                                  extra_headers);
           }
         }
       }
     }
   }
 #endif
 #endif
 }
 
+// If a prerendered page exists for |url|, replace the page at |target_contents|
+// with it.
+bool SwapInPrerender(TabContentsWrapper* target_contents, const GURL& url) {
+  prerender::PrerenderManager* prerender_manager =
+      prerender::PrerenderManagerFactory::GetForProfile(
+          target_contents->profile());
+  if (!prerender_manager)

[Peter Kasting, 2012/03/08 20:56:38]

Nit: Shorter:

  return prerender_manager && prerender_manager->MaybeUsePrerenderedPage(
      target_contents->web_contents(), url);

+    return false;
+  return prerender_manager->MaybeUsePrerenderedPage(
+      target_contents->web_contents(), url);
+}
+
 }  // namespace
 
 namespace browser {
 
 NavigateParams::NavigateParams(
     Browser* a_browser,
     const GURL& a_url,
     content::PageTransition a_transition)
     : url(a_url),
       target_contents(NULL),
@@ skipping 154 matching lines @@
     }
 
     if (user_initiated) {
       params->target_contents->web_contents()->GetRenderViewHost()->
           GetDelegate()->OnUserGesture();
     }
 
     InitializeExtraHeaders(params, params->target_contents->profile(),
                            &extra_headers);
 
+    if (SwapInPrerender(params->target_contents, url))
+      return;
+
     // Try to handle non-navigational URLs that popup dialogs and such, these
     // should not actually navigate.
     if (!HandleNonNavigationAboutURL(url)) {
       // Perform the actual navigation, tracking whether it came from the
       // renderer.
 
       LoadURLInContents(params->target_contents->web_contents(),
                         url, params, extra_headers);
     }
   } else {
@@ skipping 132 matching lines @@
       popup_bounds.height() > max_height ||
       popup_bounds.width() == 0 ||
       popup_bounds.height() == 0) {
     return NEW_FOREGROUND_TAB;
   }
   return NEW_POPUP;
 }
 #endif
 
 }  // namespace browser