WebUI TaskManager: make it default on Chrome OS

chrome/browser/prerender/prerender_browsertest.cc

Index: chrome/browser/prerender/prerender_browsertest.cc
diff --git a/chrome/browser/prerender/prerender_browsertest.cc b/chrome/browser/prerender/prerender_browsertest.cc
index 819a822a0222443bb912f86d4e7d175c66c26e8e..77858d1855bbc3bc675515ec19920e8e602a84cc 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -19,6 +19,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/browser/task_manager/task_manager.h"
+#include "chrome/browser/task_manager/task_manager_browsertest_util.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
@@ -1053,6 +1054,8 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest,
 IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, PrerenderTaskManager) {
   // Show the task manager. This populates the model.
   browser()->window()->ShowTaskManager();
+  // Wait for the model of task manager to start.
+  TaskManagerBrowserTestUtil::WaitForResourceChange(2);
 
   // Start with two resources.
   PrerenderTestURL("files/prerender/prerender_page.html", FINAL_STATUS_USED, 1);