Recreate the loader as soon as it is deleted and ensure that it does not become stale.

chrome/browser/instant/instant_browsertest.cc

Index: chrome/browser/instant/instant_browsertest.cc
diff --git a/chrome/browser/instant/instant_browsertest.cc b/chrome/browser/instant/instant_browsertest.cc
index f3f8271ae5163ed89666a0d0c633356cc1f2c7d1..e25e91bc8b2dc454a459503cb1cc91b075d5ce4b 100644
--- a/chrome/browser/instant/instant_browsertest.cc
+++ b/chrome/browser/instant/instant_browsertest.cc
@@ -237,11 +237,14 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnSubmitEvent) {
   // Commit the search by pressing Enter.
   browser()->window()->GetLocationBar()->AcceptInput();
 
-  // After the commit, Instant should not be showing, or even have a preview.
-  EXPECT_FALSE(instant()->GetPreviewContents());
+  // After the commit, Instant should not be showing.
   EXPECT_FALSE(instant()->IsCurrent());
   EXPECT_FALSE(instant()->is_showing());
 
+  // The old loader is deleted and a new one is created.
+  EXPECT_TRUE(instant()->GetPreviewContents());
+  EXPECT_NE(instant()->GetPreviewContents(), preview_tab);
+
   // Check that the current active tab is indeed what was once the preview.
   EXPECT_EQ(preview_tab, chrome::GetActiveTabContents(browser()));
 
@@ -295,11 +298,14 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnCancelEvent) {
   EXPECT_TRUE(ui_test_utils::BringBrowserWindowToFront(browser()));
   ui_test_utils::ClickOnView(browser(), VIEW_ID_TAB_CONTAINER);
 
-  // After the commit, Instant should not be showing, or even have a preview.
-  EXPECT_FALSE(instant()->GetPreviewContents());
+  // After the commit, Instant should not be showing.
   EXPECT_FALSE(instant()->IsCurrent());
   EXPECT_FALSE(instant()->is_showing());
 
+  // The old loader is deleted and a new one is created.
+  EXPECT_TRUE(instant()->GetPreviewContents());
+  EXPECT_NE(instant()->GetPreviewContents(), preview_tab);
+
   // Check that the current active tab is indeed what was once the preview.
   EXPECT_EQ(preview_tab, chrome::GetActiveTabContents(browser()));
 
@@ -350,6 +356,28 @@ IN_PROC_BROWSER_TEST_F(InstantTest, OnResizeEvent) {
   EXPECT_LT(0, height_);
 }
 
+// Tests that the instant loader is refreshed when it gets stale but is not

[sreeram, 2012/08/22 17:39:35]

Also, why put this test here, in the middle of the file? Seems logical to add
new tests (that are not obviously part of an existing group) to the bottom of
the file.

[sreeram, 2012/08/22 17:39:35]

Tests -> Test
instant -> Instant

I'd reword this comment slightly, since you are not actually testing the "when
it gets stale" part:
// Test that the Instant loader can be refreshed, but not if it's showing.

[Shishir, 2012/08/23 18:26:33]

Done.

[Shishir, 2012/08/23 18:26:33]

Done.

+// refreshed if it is showing.
+IN_PROC_BROWSER_TEST_F(InstantTest, InstantLoaderRefresh) {
+  ASSERT_NO_FATAL_FAILURE(SetupInstant("instant.html"));
+  instant()->OnAutocompleteGotFocus();
+  WaitFor(chrome::NOTIFICATION_INSTANT_SUPPORT_DETERMINED);
+
+  // Instant is not showing, so a refresh should create a new the preview

[sreeram, 2012/08/22 17:39:35]

a new the preview -> a new preview

[Shishir, 2012/08/23 18:26:33]

Done.

+  // contents.
+  instant()->RefreshLoader();
+  WaitFor(chrome::NOTIFICATION_INSTANT_SUPPORT_DETERMINED);

[sreeram, 2012/08/22 17:39:35]

Put in a comment about why we are not checking EXPECT_NE(before, after). I.e.,
because after deleting and recreating, we could end up with the same address.

[Shishir, 2012/08/23 18:26:33]

Done.

+
+  // Show instant.

[sreeram, 2012/08/22 17:39:35]

instant -> Instant

[Shishir, 2012/08/23 18:26:33]

Done.

+  SetOmniboxText("query");
+  WaitFor(chrome::NOTIFICATION_INSTANT_CONTROLLER_SHOWN);
+  TabContents* preview_tab = instant()->GetPreviewContents();
+
+  // Refresh the loader, the preview contents should remain the same.
+  instant()->RefreshLoader();
+  EXPECT_EQ(preview_tab, instant()->GetPreviewContents());
+}
+
 // Test that the INSTANT_COMPLETE_NOW behavior works as expected.
 IN_PROC_BROWSER_TEST_F(InstantTest, SuggestionIsCompletedNow) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant("instant.html"));