Fix and re-enable PrerenderTaskManager test

chrome/browser/prerender/prerender_browsertest.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 <deque>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/prefs/pref_service.h"
@@ skipping 1871 matching lines @@
 
   // Make sure the PrerenderContents for the next urls are now in the manager
   // and not pending. One and only one of the URLs (the last seen) should be the
   // active entry.
   bool url_b_is_active_prerender = UrlIsInPrerenderManager(kHtmlFileB);
   bool url_c_is_active_prerender = UrlIsInPrerenderManager(kHtmlFileC);
   EXPECT_TRUE(url_b_is_active_prerender && url_c_is_active_prerender);
 }
 
 // See crbug.com/131836.
-IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, DISABLED_PrerenderTaskManager) {
+IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderTaskManager) {
   // Show the task manager. This populates the model.
   chrome::OpenTaskManager(current_browser());
   // Wait for the model of task manager to start.
   TaskManagerBrowserTestUtil::WaitForWebResourceChange(1);
 
   // Start with two resources.
   PrerenderTestURL("files/prerender/prerender_page.html", FINAL_STATUS_USED, 1);
 
   // One of the resources that has a WebContents associated with it should have
   // the Prerender prefix.
   const string16 prefix =
       l10n_util::GetStringFUTF16(IDS_TASK_MANAGER_PRERENDER_PREFIX, string16());
   string16 prerender_title;
   int num_prerender_tabs = 0;
 
-  const TaskManagerModel* model = GetModel();
+  TaskManagerModel* model = GetModel();
+  // The task manager caches values. Force the titles to be fresh.
+  model->Refresh();
   for (int i = 0; i < model->ResourceCount(); ++i) {
     if (model->GetResourceWebContents(i)) {
       prerender_title = model->GetResourceTitle(i);
       if (StartsWith(prerender_title, prefix, true))
         ++num_prerender_tabs;
     }
   }
   EXPECT_EQ(1, num_prerender_tabs);
   const string16 prerender_page_title = prerender_title.substr(prefix.length());
 
   NavigateToDestURL();
 
   // There should be no tabs with the Prerender prefix.
   const string16 tab_prefix =
       l10n_util::GetStringFUTF16(IDS_TASK_MANAGER_TAB_PREFIX, string16());
   num_prerender_tabs = 0;
   int num_tabs_with_prerender_page_title = 0;
+  model->Refresh();
   for (int i = 0; i < model->ResourceCount(); ++i) {
     if (model->GetResourceWebContents(i)) {
       string16 tab_title = model->GetResourceTitle(i);
       if (StartsWith(tab_title, prefix, true)) {
         ++num_prerender_tabs;
       } else {
         EXPECT_TRUE(StartsWith(tab_title, tab_prefix, true));
 
         // The prerender tab should now be a normal tab but the title should be
         // the same. Depending on timing, there may be more than one of these.
@@ skipping 1010 matching lines @@
   PrerenderTestURL("files/prerender/prerender_page.html",
                    FINAL_STATUS_PAGE_BEING_CAPTURED, 1);
   WebContents* web_contents =
       current_browser()->tab_strip_model()->GetActiveWebContents();
   web_contents->IncrementCapturerCount();
   NavigateToDestURLWithDisposition(CURRENT_TAB, false);
   web_contents->DecrementCapturerCount();
 }
 
 }  // namespace prerender