Fix: Prerendering was confusing SessionService to not save sessionStorage.

chrome/browser/sessions/session_restore_browsertest.cc

Index: chrome/browser/sessions/session_restore_browsertest.cc
diff --git a/chrome/browser/sessions/session_restore_browsertest.cc b/chrome/browser/sessions/session_restore_browsertest.cc
index ed7044033254e521ea30c144fc05b7ac6f4349b5..b3a9864f3f441a243ccf1146b8df052d6a417dde 100644
--- a/chrome/browser/sessions/session_restore_browsertest.cc
+++ b/chrome/browser/sessions/session_restore_browsertest.cc
@@ -23,6 +23,7 @@
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/chrome_switches.h"
@@ -852,3 +853,43 @@ IN_PROC_BROWSER_TEST_F(SessionRestoreTest, SessionStorage) {
   EXPECT_EQ(session_storage_persistent_id,
             restored_session_storage_persistent_id);
 }
+
+IN_PROC_BROWSER_TEST_F(SessionRestoreTest, SessionStorageAfterTabReplace) {
+  // Simulate what prerendering does: create a new TabContents with the same
+  // SessionStorageNamespace as an existing tab, then replace the tab with it.
+  {
+    content::NavigationController* controller =
+        &chrome::GetActiveWebContents(browser())->GetController();
+    ASSERT_TRUE(controller->GetDefaultSessionStorageNamespace());
+
+    content::SessionStorageNamespaceMap session_storage_namespace_map;
+    session_storage_namespace_map[""] =
+        controller->GetDefaultSessionStorageNamespace();
+    scoped_ptr<content::WebContents> web_contents(
+        content::WebContents::CreateWithSessionStorage(
+            browser()->profile(), NULL, MSG_ROUTING_NONE, NULL,
+            session_storage_namespace_map));
+
+    TabStripModel* tab_strip_model = browser()->tab_strip_model();
+    // We only need to create a TabContents because ReplaceTabContentsAt wants
+    // one. We don't need any of the helpers TabContents provides.
+    scoped_ptr<TabContents> old_tab_contents(
+        tab_strip_model->ReplaceTabContentsAt(
+            tab_strip_model->active_index(),
+            TabContents::Factory::CreateTabContents(web_contents.release())));
+    // Navigate with the new tab.
+    ui_test_utils::NavigateToURL(browser(), url2_);
+    // old_tab_contents goes out of scope.
+  }
+
+  // Check that the sessionStorage data is going to be persisted.
+  content::NavigationController* controller =
+      &chrome::GetActiveWebContents(browser())->GetController();
+  EXPECT_TRUE(
+      controller->GetDefaultSessionStorageNamespace()->should_persist());
+
+  // Quit and restore. Check that no extra tabs were created.
+  Browser* new_browser = QuitBrowserAndRestore(browser(), 1);
+  ASSERT_EQ(1u, BrowserList::size());
+  EXPECT_EQ(1, new_browser->tab_strip_model()->count());
+}