[Panels refactor] Track Panels in TaskManager now that they are not under the tab contents umbrella.

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 104dffc6be902a5be48e1d5b32b4b80067efae4b..929b2c4ba58af709fe72e8fc8d079c6d62ccb1c1 100644
--- a/chrome/browser/prerender/prerender_browsertest.cc
+++ b/chrome/browser/prerender/prerender_browsertest.cc
@@ -1509,7 +1509,7 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, DISABLED_PrerenderTaskManager) {
 
   const TaskManagerModel* model = GetModel();
   for (int i = 0; i < model->ResourceCount(); ++i) {
-    if (model->GetResourceTabContents(i)) {
+    if (model->GetResourceWebContents(i)) {
       prerender_title = model->GetResourceTitle(i);
       if (StartsWith(prerender_title, prefix, true))
         ++num_prerender_tabs;
@@ -1526,7 +1526,7 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, DISABLED_PrerenderTaskManager) {
   num_prerender_tabs = 0;
   int num_tabs_with_prerender_page_title = 0;
   for (int i = 0; i < model->ResourceCount(); ++i) {
-    if (model->GetResourceTabContents(i)) {
+    if (model->GetResourceWebContents(i)) {
       string16 tab_title = model->GetResourceTitle(i);
       if (StartsWith(tab_title, prefix, true)) {
         ++num_prerender_tabs;