Fix regression with back-button not working on prerendered and instant pages.

chrome/browser/prerender/prerender_browsertest.cc

 // Copyright (c) 2011 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 "base/command_line.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 455 matching lines @@
         &click_prerendered_link_result));
     EXPECT_TRUE(click_prerendered_link_result);
 
     // If the prerender contents has not been destroyed, run message loop.
     if (GetPrerenderContents() != NULL) {
       prerender_contents->set_quit_message_loop_on_destruction(true);
       ui_test_utils::RunMessageLoop();
     }
   }
 
+  void OpenDestUrlViaClick() const {
+    // Make sure in navigating we have a URL to use in the PrerenderManager.
+    TestPrerenderContents* prerender_contents = GetPrerenderContents();
+    ASSERT_TRUE(prerender_contents != NULL);
+    prerender_contents->set_quit_message_loop_on_destruction(false);
+
+    bool click_prerendered_link_result = false;
+    ASSERT_TRUE(ui_test_utils::ExecuteJavaScriptAndExtractBool(
+        browser()->GetSelectedTabContents()->render_view_host(), L"",
+        L"window.domAutomationController.send(ClickOpenLink())",
+        &click_prerendered_link_result));
+    EXPECT_TRUE(click_prerendered_link_result);
+
+    // If the prerender contents has not been destroyed, run message loop.
+    if (GetPrerenderContents() != NULL) {
+      prerender_contents->set_quit_message_loop_on_destruction(true);
+      ui_test_utils::RunMessageLoop();
+    }
+  }
+
   // Should be const but test_server()->GetURL(...) is not const.
   void NavigateToURL(const std::string& dest_html_file) {
     GURL dest_url = test_server()->GetURL(dest_html_file);
     NavigateToURLImpl(dest_url, CURRENT_TAB);
   }
 
   bool UrlIsInPrerenderManager(const std::string& html_file) {
     GURL dest_url = test_server()->GetURL(html_file);
     return (prerender_manager()->FindEntry(dest_url) != NULL);
   }
@@ skipping 1119 matching lines @@
                    FINAL_STATUS_CANCELLED,
                    1);
   // Post a task to cancel all the prerenders.
   MessageLoop::current()->PostTask(FROM_HERE,
                                    NewRunnableFunction(CancelAllPrerenders,
                                                        prerender_manager()));
   ui_test_utils::RunMessageLoop();
   EXPECT_TRUE(GetPrerenderContents() == NULL);
 }
 
+IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, BackToPrerenderedPage) {
+  PrerenderTestURL("files/prerender/prerender_page_with_link.html",
+                   FINAL_STATUS_USED,
+                   1);
+
+  OpenDestUrlViaClick();
+
+  // Click on the link in the page and wait for it to commit
+  {
+    ui_test_utils::WindowedNotificationObserver new_page_observer(
+        content::NOTIFICATION_NAV_ENTRY_COMMITTED,
+        NotificationService::AllSources());
+    bool click_link_result = false;
+    ASSERT_TRUE(ui_test_utils::ExecuteJavaScriptAndExtractBool(
+        browser()->GetSelectedTabContents()->render_view_host(), L"",
+        L"window.domAutomationController.send(ClickOpenLink())",
+        &click_link_result));
+    EXPECT_TRUE(click_link_result);
+    new_page_observer.Wait();
+  }
+
+  // Now, go back to the prerendered page.
+  {
+    ui_test_utils::WindowedNotificationObserver back_nav_observer(
+        content::NOTIFICATION_NAV_ENTRY_COMMITTED,
+        NotificationService::AllSources());
+    browser()->GoBack(CURRENT_TAB);
+    back_nav_observer.Wait();

[mmenke, 2011/08/09 14:54:03]

Maybe run a script here or something, to make sure the correct page has really
loaded?

[cbentzel, 2011/08/09 15:42:39]

Perhaps. I tried using a title watcher but that hung. May just call javascript
here.

[mmenke, 2011/08/09 15:48:37]

I was thinking of calling Javascript, but the title watcher strikes me as a
better idea.  Both "prerender_page_with_link.html" and "prerender_page.html"
have the same title.  Maybe that's why it hung?

[mmenke, 2011/08/09 15:49:35]

Oops...No they don't.  That is odd.

+  }
+}
+
 }  // namespace prerender