Reload Instant NTP and Instant-process tabs on search url change

. Add a default impl of instant_service_observer.

. Move pref change listener for default search provider to
instant_service and pass to browser_instant_controller and
instant_ntp_prerenderer via instant_service_observer.

. Add a search-domain-check listener to instant_service in a similar
manner.

. Replaced ReloadStaleNTP, PreloadInstantNTP etc with ReloadInstantNTP

. Introduce InstantUnitTestBase
  - InstantServiceTest and BrowserInstantControllerTest are subclasses.

. InstantService Unit Test
  - Use a mock observer to verify the search provider change and 
    google url update is triggered on observers.
  - Verify the prerendered NTP is reloaded.

. BrowserInstantController Unit Test
  - Moved the tab reload test from interactive ui test to 
     BrowserInstantControllerTest.


R=jered@chromium.org, samarth@chromium.org
TBR=sky@chromium.org
BUG=254206

Review URL: https://chromiumcodereview.appspot.com/20388003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225063 0039d316-1c4b-4281-b951-d872f2087c98

19 files changed, 616 insertions, 219 deletions

diff --git a/chrome/browser/search/instant_service.cc b/chrome/browser/search/instant_service.cc
index 62e8580..c50d271 100644
--- a/chrome/browser/search/instant_service.cc
+++ b/chrome/browser/search/instant_service.cc
@@ -7,6 +7,7 @@
 #include <vector>
 
 #include "base/logging.h"
+#include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/history/history_notifications.h"
@@ -19,18 +20,25 @@
 #include "chrome/browser/search/local_ntp_source.h"
 #include "chrome/browser/search/most_visited_iframe_source.h"
 #include "chrome/browser/search/search.h"
+#include "chrome/browser/search_engines/template_url.h"
+#include "chrome/browser/search_engines/template_url_service.h"
+#include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/themes/theme_properties.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/webui/favicon_source.h"
 #include "chrome/browser/ui/webui/ntp/thumbnail_source.h"
 #include "chrome/browser/ui/webui/theme_source.h"
+#include "chrome/common/pref_names.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/url_data_source.h"
 #include "grit/theme_resources.h"
+#include "net/base/net_util.h"
 #include "net/url_request/url_request.h"
 #include "ui/gfx/color_utils.h"
 #include "ui/gfx/image/image_skia.h"
@@ -57,7 +65,7 @@ RGBAColor SkColorToRGBAColor(const SkColor& sKColor) {
 
 InstantService::InstantService(Profile* profile)
     : profile_(profile),
-      ntp_prerenderer_(profile, profile->GetPrefs()),
+      ntp_prerenderer_(profile, this, profile->GetPrefs()),
       browser_instant_controller_object_count_(0),
       weak_ptr_factory_(this) {
   // Stub for unit tests.
@@ -90,15 +98,25 @@ InstantService::InstantService(Profile* profile)
                  content::Source<ThemeService>(
                      ThemeServiceFactory::GetForProfile(profile_)));
 
-  content::URLDataSource::Add(profile, new ThemeSource(profile));
+  content::URLDataSource::Add(profile_, new ThemeSource(profile_));
 #endif  // defined(ENABLE_THEMES)
 
-  content::URLDataSource::Add(profile, new ThumbnailSource(profile, false));
-  content::URLDataSource::Add(profile, new ThumbnailSource(profile, true));
-  content::URLDataSource::Add(profile, new FaviconSource(
-      profile, FaviconSource::FAVICON));
-  content::URLDataSource::Add(profile, new LocalNtpSource(profile));
-  content::URLDataSource::Add(profile, new MostVisitedIframeSource());
+
+  content::URLDataSource::Add(profile_, new ThumbnailSource(profile_, false));
+  content::URLDataSource::Add(profile_, new ThumbnailSource(profile_, true));
+  content::URLDataSource::Add(
+      profile_, new FaviconSource(profile_, FaviconSource::FAVICON));
+  content::URLDataSource::Add(profile_, new LocalNtpSource(profile_));
+  content::URLDataSource::Add(profile_, new MostVisitedIframeSource());
+
+  profile_pref_registrar_.Init(profile_->GetPrefs());
+  profile_pref_registrar_.Add(
+      prefs::kDefaultSearchProviderID,
+      base::Bind(&InstantService::OnDefaultSearchProviderChanged,
+                 base::Unretained(this)));
+
+  registrar_.Add(this, chrome::NOTIFICATION_GOOGLE_URL_UPDATED,
+                 content::Source<Profile>(profile_->GetOriginalProfile()));
   registrar_.Add(this, chrome::NOTIFICATION_PROFILE_DESTROYED,
                  content::Source<Profile>(profile_));
 }
@@ -195,7 +213,7 @@ void InstantService::OnBrowserInstantControllerCreated() {
   ++browser_instant_controller_object_count_;
 
   if (browser_instant_controller_object_count_ == 1)
-    ntp_prerenderer_.PreloadInstantNTP();
+    ntp_prerenderer_.ReloadInstantNTP();
 }
 
 void InstantService::OnBrowserInstantControllerDestroyed() {
@@ -255,6 +273,12 @@ void InstantService::Observe(int type,
         ntp_prerenderer_.DeleteNTPContents();
       break;
     }
+    case chrome::NOTIFICATION_GOOGLE_URL_UPDATED: {
+      OnGoogleURLUpdated(
+          content::Source<Profile>(source).ptr(),
+          content::Details<GoogleURLTracker::UpdatedDetails>(details).ptr());
+      break;
+    }
     default:
       NOTREACHED() << "Unexpected notification type in InstantService.";
   }
@@ -391,6 +415,44 @@ void InstantService::OnThemeChanged(ThemeService* theme_service) {
                     ThemeInfoChanged(*theme_info_));
 }
 
+void InstantService::OnGoogleURLUpdated(
+    Profile* profile,
+    GoogleURLTracker::UpdatedDetails* details) {
+  GURL last_prompted_url(
+      profile->GetPrefs()->GetString(prefs::kLastPromptedGoogleURL));
+
+  // See GoogleURLTracker::OnURLFetchComplete().
+  // last_prompted_url.is_empty() indicates very first run of Chrome. So there
+  // is no need to notify, as there won't be any old state.
+  if (last_prompted_url.is_empty())
+    return;
+
+  // Only the scheme changed. Ignore it since we do not prompt the user in this
+  // case.
+  if (net::StripWWWFromHost(details->first) ==
+      net::StripWWWFromHost(details->second))
+    return;
+
+  FOR_EACH_OBSERVER(InstantServiceObserver, observers_, GoogleURLUpdated());
+}
+
+void InstantService::OnDefaultSearchProviderChanged(
+    const std::string& pref_name) {
+  DCHECK_EQ(pref_name, std::string(prefs::kDefaultSearchProviderID));
+  const TemplateURL* template_url = TemplateURLServiceFactory::GetForProfile(
+      profile_)->GetDefaultSearchProvider();
+  if (!template_url) {
+    // A NULL |template_url| could mean either this notification is sent during
+    // the browser start up operation or the user now has no default search
+    // provider. There is no way for the user to reach this state using the
+    // Chrome settings. Only explicitly poking at the DB or bugs in the Sync
+    // could cause that, neither of which we support.
+    return;
+  }
+  FOR_EACH_OBSERVER(
+      InstantServiceObserver, observers_, DefaultSearchProviderChanged());
+}
+
 InstantNTPPrerenderer* InstantService::ntp_prerenderer() {
   return &ntp_prerenderer_;
 }
diff --git a/chrome/browser/search/instant_service.h b/chrome/browser/search/instant_service.h
index f8c88e5..f876c4a 100644
--- a/chrome/browser/search/instant_service.h
+++ b/chrome/browser/search/instant_service.h
@@ -17,6 +17,8 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "base/prefs/pref_change_registrar.h"
+#include "chrome/browser/google/google_url_tracker.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/browser/ui/search/instant_ntp_prerenderer.h"
 #include "chrome/common/instant_types.h"
@@ -25,10 +27,8 @@
 #include "content/public/browser/notification_registrar.h"
 
 class GURL;
-class InstantExtendedTest;
 class InstantIOContext;
 class InstantServiceObserver;
-class InstantTestBase;
 class Profile;
 class ThemeService;
 
@@ -104,7 +104,9 @@ class InstantService : public BrowserContextKeyedService,
 
  private:
   friend class InstantExtendedTest;
+  friend class InstantServiceTest;
   friend class InstantTestBase;
+  friend class InstantUnitTestBase;
 
   FRIEND_TEST_ALL_PREFIXES(InstantExtendedNetworkTest,
                            NTPReactsToNetworkChanges);
@@ -133,6 +135,11 @@ class InstantService : public BrowserContextKeyedService,
   // Theme changed notification handler.
   void OnThemeChanged(ThemeService* theme_service);
 
+  void OnGoogleURLUpdated(Profile* profile,
+                          GoogleURLTracker::UpdatedDetails* details);
+
+  void OnDefaultSearchProviderChanged(const std::string& pref_name);
+
   // Used by tests.
   InstantNTPPrerenderer* ntp_prerenderer();
 
@@ -151,6 +158,8 @@ class InstantService : public BrowserContextKeyedService,
 
   content::NotificationRegistrar registrar_;
 
+  PrefChangeRegistrar profile_pref_registrar_;
+
   scoped_refptr<InstantIOContext> instant_io_context_;
 
   InstantNTPPrerenderer ntp_prerenderer_;
diff --git a/chrome/browser/search/instant_service_observer.cc b/chrome/browser/search/instant_service_observer.cc
new file mode 100644
index 0000000..02e8856
--- /dev/null
+++ b/chrome/browser/search/instant_service_observer.cc
@@ -0,0 +1,18 @@
+// Copyright 2013 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 "chrome/browser/search/instant_service_observer.h"
+
+void InstantServiceObserver::ThemeInfoChanged(const ThemeBackgroundInfo&) {
+}
+
+void InstantServiceObserver::MostVisitedItemsChanged(
+    const std::vector<InstantMostVisitedItem>&) {
+}
+
+void InstantServiceObserver::DefaultSearchProviderChanged() {
+}
+
+void InstantServiceObserver::GoogleURLUpdated() {
+}
diff --git a/chrome/browser/search/instant_service_observer.h b/chrome/browser/search/instant_service_observer.h
index c282c93..7d88b1a 100644
--- a/chrome/browser/search/instant_service_observer.h
+++ b/chrome/browser/search/instant_service_observer.h
@@ -14,11 +14,19 @@ struct ThemeBackgroundInfo;
 class InstantServiceObserver {
  public:
   // Indicates that the user's custom theme has changed in some way.
-  virtual void ThemeInfoChanged(const ThemeBackgroundInfo&) = 0;
+  virtual void ThemeInfoChanged(const ThemeBackgroundInfo&);
 
   // Indicates that the most visited items has changed.
   virtual void MostVisitedItemsChanged(
-      const std::vector<InstantMostVisitedItem>&) = 0;
+      const std::vector<InstantMostVisitedItem>&);
+
+  // Indicates that the default search provider changed.
+  virtual void DefaultSearchProviderChanged();
+
+  // Indicates that the Google URL has changed as a result of searchdomaincheck.
+  // Note that the search domain change triggers a yellow infobar at the top of
+  // the page, and the actual change is triggered after the user accepts.
+  virtual void GoogleURLUpdated();
 
  protected:
   virtual ~InstantServiceObserver() {}
diff --git a/chrome/browser/search/instant_service_unittest.cc b/chrome/browser/search/instant_service_unittest.cc
new file mode 100644
index 0000000..1ae497e
--- /dev/null
+++ b/chrome/browser/search/instant_service_unittest.cc
@@ -0,0 +1,101 @@
+// Copyright 2013 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 <string>
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string_util.h"
+#include "chrome/browser/search/instant_service.h"
+#include "chrome/browser/search/instant_service_observer.h"
+#include "chrome/browser/search/instant_unittest_base.h"
+#include "chrome/browser/search/search.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/browser_window.h"
+#include "chrome/browser/ui/host_desktop.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace chrome {
+
+namespace {
+
+class MockInstantServiceObserver : public InstantServiceObserver {
+ public:
+  MOCK_METHOD0(DefaultSearchProviderChanged, void());
+  MOCK_METHOD0(GoogleURLUpdated, void());
+};
+
+class MockWebContentsObserver : public content::WebContentsObserver {
+ public:
+  MOCK_METHOD1(WebContentsDestroyed, void(content::WebContents*));
+
+  // Dumb override to make MSVC happy.
+  void Observe_(content::WebContents* contents) {
+    content::WebContentsObserver::Observe(contents);
+  }
+
+ protected:
+  friend class InstantServiceTest;
+  FRIEND_TEST_ALL_PREFIXES(InstantServiceTest,
+      DispatchDefaultSearchProviderChanged);
+  FRIEND_TEST_ALL_PREFIXES(InstantServiceTest, DispatchGoogleURLUpdated);
+};
+
+class InstantServiceTest : public InstantUnitTestBase {
+ protected:
+  virtual void SetUp() OVERRIDE {
+    InstantUnitTestBase::SetUp();
+
+    instant_service_observer_.reset(new MockInstantServiceObserver());
+    instant_service_->AddObserver(instant_service_observer_.get());
+
+    instant_ntp_contents_observer_.reset(new MockWebContentsObserver());
+    instant_ntp_contents_observer_->Observe_(
+        instant_service_->GetNTPContents());
+  }
+
+  virtual void TearDown() OVERRIDE {
+    instant_service_->RemoveObserver(instant_service_observer_.get());
+    instant_ntp_contents_observer_->Observe_(NULL);
+    InstantUnitTestBase::TearDown();
+  }
+
+  scoped_ptr<MockInstantServiceObserver> instant_service_observer_;
+  scoped_ptr<MockWebContentsObserver> instant_ntp_contents_observer_;
+};
+
+TEST_F(InstantServiceTest, DispatchDefaultSearchProviderChanged) {
+  EXPECT_CALL(*instant_service_observer_.get(), DefaultSearchProviderChanged())
+      .Times(1);
+  EXPECT_CALL(*instant_ntp_contents_observer_.get(),
+              WebContentsDestroyed(instant_service_->GetNTPContents()))
+      .Times(1);
+
+  GURL ntp_url = instant_service_->GetNTPContents()->GetURL();
+  const std::string& new_base_url = "https://bar.com/";
+  SetDefaultSearchProvider(new_base_url);
+  GURL new_ntp_url = instant_service_->GetNTPContents()->GetURL();
+  EXPECT_NE(ntp_url, new_ntp_url);
+  EXPECT_TRUE(StartsWithASCII(new_ntp_url.spec(), new_base_url, true));
+}
+
+TEST_F(InstantServiceTest, DispatchGoogleURLUpdated) {
+  EXPECT_CALL(*instant_service_observer_.get(), GoogleURLUpdated()).Times(1);
+  EXPECT_CALL(*instant_ntp_contents_observer_.get(),
+              WebContentsDestroyed(instant_service_->GetNTPContents()))
+      .Times(1);
+
+  GURL ntp_url = instant_service_->GetNTPContents()->GetURL();
+  const std::string& new_base_url = "https://www.google.es/";
+  NotifyGoogleBaseURLUpdate(new_base_url);
+  GURL new_ntp_url = instant_service_->GetNTPContents()->GetURL();
+  EXPECT_NE(ntp_url, new_ntp_url);
+  EXPECT_TRUE(StartsWithASCII(new_ntp_url.spec(), new_base_url, true));
+}
+
+}  // namespace
+
+}  // namespace chrome
diff --git a/chrome/browser/search/instant_unittest_base.cc b/chrome/browser/search/instant_unittest_base.cc
new file mode 100644
index 0000000..1842ac3
--- /dev/null
+++ b/chrome/browser/search/instant_unittest_base.cc
@@ -0,0 +1,85 @@
+// Copyright 2013 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 "chrome/browser/search/instant_unittest_base.h"
+#include <string>
+
+#include "base/basictypes.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/google/google_url_tracker.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/search/instant_service.h"
+#include "chrome/browser/search/instant_service_factory.h"
+#include "chrome/browser/search/search.h"
+#include "chrome/browser/search_engines/search_terms_data.h"
+#include "chrome/browser/search_engines/template_url.h"
+#include "chrome/browser/search_engines/template_url_service.h"
+#include "chrome/browser/search_engines/template_url_service_factory.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/test/base/browser_with_test_window_test.h"
+#include "chrome/test/base/testing_pref_service_syncable.h"
+#include "chrome/test/base/ui_test_utils.h"
+#include "content/public/browser/notification_details.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/notification_source.h"
+
+void InstantUnitTestBase::SetUp() {
+  chrome::EnableInstantExtendedAPIForTesting();
+  BrowserWithTestWindowTest::SetUp();
+
+  TemplateURLServiceFactory::GetInstance()->SetTestingFactoryAndUse(
+      profile(), &TemplateURLServiceFactory::BuildInstanceFor);
+  template_url_service_ = TemplateURLServiceFactory::GetForProfile(profile());
+  ui_test_utils::WaitForTemplateURLServiceToLoad(template_url_service_);
+
+  UIThreadSearchTermsData::SetGoogleBaseURL("https://www.google.com/");
+  TestingPrefServiceSyncable* pref_service = profile()->GetTestingPrefService();
+  pref_service->SetUserPref(prefs::kLastPromptedGoogleURL,
+                            new base::StringValue("https://www.google.com/"));
+  SetDefaultSearchProvider("{google:baseURL}");
+  instant_service_ = InstantServiceFactory::GetForProfile(profile());
+}
+
+void InstantUnitTestBase::TearDown() {
+  UIThreadSearchTermsData::SetGoogleBaseURL("");
+  BrowserWithTestWindowTest::TearDown();
+}
+
+void InstantUnitTestBase::SetDefaultSearchProvider(
+    const std::string& base_url) {
+  TemplateURLData data;
+  data.SetURL(base_url + "url?bar={searchTerms}");
+  data.instant_url = base_url + "instant?"
+                     "{google:omniboxStartMarginParameter}foo=foo#foo=foo&strk";
+  data.alternate_urls.push_back(base_url + "alt#quux={searchTerms}");
+  data.search_terms_replacement_key = "strk";
+
+  TemplateURL* template_url = new TemplateURL(profile(), data);
+  // Takes ownership of |template_url|.
+  template_url_service_->Add(template_url);
+  template_url_service_->SetDefaultSearchProvider(template_url);
+}
+
+void InstantUnitTestBase::NotifyGoogleBaseURLUpdate(
+    const std::string& new_google_base_url) {
+  // GoogleURLTracker is not created in tests.
+  // (See GoogleURLTrackerFactory::ServiceIsNULLWhileTesting())
+  // For determining google:baseURL for NTP, the following is used:
+  // UIThreadSearchTermsData::GoogleBaseURLValue()
+  // For simulating test behavior, this is overridden below.
+  UIThreadSearchTermsData::SetGoogleBaseURL(new_google_base_url);
+  GoogleURLTracker::UpdatedDetails details(GURL("https://www.google.com/"),
+                                           GURL(new_google_base_url));
+  content::NotificationService::current()->Notify(
+      chrome::NOTIFICATION_GOOGLE_URL_UPDATED,
+      content::Source<Profile>(profile()->GetOriginalProfile()),
+      content::Details<GoogleURLTracker::UpdatedDetails>(&details));
+}
+
+
+bool InstantUnitTestBase::IsInstantServiceObserver(
+    InstantServiceObserver* observer) {
+  return instant_service_->observers_.HasObserver(observer);
+}
+
diff --git a/chrome/browser/search/instant_unittest_base.h b/chrome/browser/search/instant_unittest_base.h
new file mode 100644
index 0000000..6e46cf9
--- /dev/null
+++ b/chrome/browser/search/instant_unittest_base.h
@@ -0,0 +1,42 @@
+// Copyright 2013 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.
+
+#ifndef CHROME_BROWSER_SEARCH_INSTANT_UNITTEST_BASE_H_
+#define CHROME_BROWSER_SEARCH_INSTANT_UNITTEST_BASE_H_
+
+#include <string>
+
+#include "chrome/browser/search/instant_service.h"
+#include "chrome/browser/search_engines/template_url_service.h"
+#include "chrome/test/base/browser_with_test_window_test.h"
+
+class InstantServiceObserver;
+
+// This class provides an extension on top of BrowserWithTestWindowTest, and
+// adds some utility methods which can be useful for various unit tests for
+// Embedded Search / Instant implementation classes.
+class InstantUnitTestBase : public BrowserWithTestWindowTest {
+ protected:
+  virtual void SetUp() OVERRIDE;
+  virtual void TearDown() OVERRIDE;
+
+  // Adds and sets the default search provider using the base_url.
+  // The base_url should have the http[s]:// prefix and a trailing / after the
+  // TLD.
+  // It will always use an instant-enabled configuration using a
+  // search_terms_replacement_key.
+  void SetDefaultSearchProvider(const std::string& base_url);
+
+  // Simulates a Google Base URL change as would happen in event of
+  // search-domain-check. Note that the GoogleURLTrackerFactory is disabled for
+  // tests, so this is required.
+  void NotifyGoogleBaseURLUpdate(const std::string& new_google_base_url);
+
+  bool IsInstantServiceObserver(InstantServiceObserver* observer);
+
+  InstantService* instant_service_;
+  TemplateURLService* template_url_service_;
+};
+
+#endif  // CHROME_BROWSER_SEARCH_INSTANT_UNITTEST_BASE_H_
diff --git a/chrome/browser/ui/OWNERS b/chrome/browser/ui/OWNERS
index d7a02c7..dfe6fff 100644
--- a/chrome/browser/ui/OWNERS
+++ b/chrome/browser/ui/OWNERS
@@ -9,6 +9,6 @@ sky@chromium.org
 per-file browser_tab_contents.*=avi@chromium.org
 
 # Instant/Search files.
-per-file browser_instant_controller.*=brettw@chromium.org
-per-file browser_instant_controller.*=jered@chromium.org
-per-file browser_instant_controller.*=samarth@chromium.org
+per-file browser_instant_controller*=brettw@chromium.org
+per-file browser_instant_controller*=jered@chromium.org
+per-file browser_instant_controller*=samarth@chromium.org
diff --git a/chrome/browser/ui/browser_instant_controller.cc b/chrome/browser/ui/browser_instant_controller.cc
index 662eca7..378d276 100644
--- a/chrome/browser/ui/browser_instant_controller.cc
+++ b/chrome/browser/ui/browser_instant_controller.cc
@@ -5,16 +5,12 @@
 #include "chrome/browser/ui/browser_instant_controller.h"
 
 #include "base/bind.h"
-#include "base/prefs/pref_service.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_web_ui.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/instant_service.h"
 #include "chrome/browser/search/instant_service_factory.h"
 #include "chrome/browser/search/search.h"
-#include "chrome/browser/search_engines/template_url.h"
-#include "chrome/browser/search_engines/template_url_service.h"
-#include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/omnibox/location_bar.h"
@@ -25,9 +21,7 @@
 #include "chrome/browser/ui/search/search_tab_helper.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/webui/ntp/app_launcher_handler.h"
-#include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
-#include "components/user_prefs/pref_registry_syncable.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/user_metrics.h"
 #include "content/public/browser/web_contents.h"
@@ -42,16 +36,12 @@ BrowserInstantController::BrowserInstantController(Browser* browser)
     : browser_(browser),
       instant_(this),
       instant_unload_handler_(browser) {
-  profile_pref_registrar_.Init(profile()->GetPrefs());
-  profile_pref_registrar_.Add(
-      prefs::kDefaultSearchProviderID,
-      base::Bind(&BrowserInstantController::OnDefaultSearchProviderChanged,
-                 base::Unretained(this)));
   browser_->search_model()->AddObserver(this);
 
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(profile());
   instant_service->OnBrowserInstantControllerCreated();
+  instant_service->AddObserver(this);
 }
 
 BrowserInstantController::~BrowserInstantController() {
@@ -59,6 +49,7 @@ BrowserInstantController::~BrowserInstantController() {
 
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(profile());
+  instant_service->RemoveObserver(this);
   instant_service->OnBrowserInstantControllerDestroyed();
 }
 
@@ -273,25 +264,20 @@ void BrowserInstantController::ModelChanged(
     instant_.InstantSupportChanged(new_state.instant_support);
 }
 
-void BrowserInstantController::OnDefaultSearchProviderChanged(
-    const std::string& pref_name) {
-  DCHECK_EQ(pref_name, std::string(prefs::kDefaultSearchProviderID));
-
-  Profile* browser_profile = profile();
-  const TemplateURL* template_url =
-      TemplateURLServiceFactory::GetForProfile(browser_profile)->
-          GetDefaultSearchProvider();
-  if (!template_url) {
-    // A NULL |template_url| could mean either this notification is sent during
-    // the browser start up operation or the user now has no default search
-    // provider. There is no way for the user to reach this state using the
-    // Chrome settings. Only explicitly poking at the DB or bugs in the Sync
-    // could cause that, neither of which we support.
-    return;
-  }
+////////////////////////////////////////////////////////////////////////////////
+// BrowserInstantController, InstantServiceObserver implementation:
+
+void BrowserInstantController::DefaultSearchProviderChanged() {
+  ReloadTabsInInstantProcess();
+}
+
+void BrowserInstantController::GoogleURLUpdated() {
+  ReloadTabsInInstantProcess();
+}
 
+void BrowserInstantController::ReloadTabsInInstantProcess() {
   InstantService* instant_service =
-      InstantServiceFactory::GetForProfile(browser_profile);
+      InstantServiceFactory::GetForProfile(profile());
   if (!instant_service)
     return;
 
diff --git a/chrome/browser/ui/browser_instant_controller.h b/chrome/browser/ui/browser_instant_controller.h
index 66598ef..a187a8c 100644
--- a/chrome/browser/ui/browser_instant_controller.h
+++ b/chrome/browser/ui/browser_instant_controller.h
@@ -9,7 +9,7 @@
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
-#include "base/prefs/pref_change_registrar.h"
+#include "chrome/browser/search/instant_service_observer.h"
 #include "chrome/browser/ui/search/instant_controller.h"
 #include "chrome/browser/ui/search/instant_unload_handler.h"
 #include "chrome/browser/ui/search/search_model_observer.h"
@@ -27,7 +27,8 @@ namespace gfx {
 class Rect;
 }
 
-class BrowserInstantController : public SearchModelObserver {
+class BrowserInstantController : public SearchModelObserver,
+                                 public InstantServiceObserver {
  public:
   explicit BrowserInstantController(Browser* browser);
   virtual ~BrowserInstantController();
@@ -91,11 +92,13 @@ class BrowserInstantController : public SearchModelObserver {
   virtual void ModelChanged(const SearchModel::State& old_state,
                             const SearchModel::State& new_state) OVERRIDE;
 
-  // Called when the default search provider changes. Revokes the searchbox API
-  // privileges for any existing WebContents (that belong to the erstwhile
-  // default search provider) by simply reloading all such WebContents. This
-  // ensures that they are reloaded in a non-privileged renderer process.
-  void OnDefaultSearchProviderChanged(const std::string& pref_name);
+  // Overridden from InstantServiceObserver:
+  virtual void DefaultSearchProviderChanged() OVERRIDE;
+  virtual void GoogleURLUpdated() OVERRIDE;
+
+  // Reloads the tabs in instant process to ensure that their privileged status
+  // is still valid.
+  void ReloadTabsInInstantProcess();
 
   // Replaces the contents at tab |index| with |new_contents| and deletes the
   // existing contents.
@@ -107,8 +110,6 @@ class BrowserInstantController : public SearchModelObserver {
   InstantController instant_;
   InstantUnloadHandler instant_unload_handler_;
 
-  PrefChangeRegistrar profile_pref_registrar_;
-
   DISALLOW_COPY_AND_ASSIGN(BrowserInstantController);
 };
 
diff --git a/chrome/browser/ui/browser_instant_controller_unittest.cc b/chrome/browser/ui/browser_instant_controller_unittest.cc
new file mode 100644
index 0000000..52540aa
--- /dev/null
+++ b/chrome/browser/ui/browser_instant_controller_unittest.cc
@@ -0,0 +1,193 @@
+// Copyright 2013 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 <string>
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_vector.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/search/instant_service.h"
+#include "chrome/browser/search/instant_service_observer.h"
+#include "chrome/browser/search/instant_unittest_base.h"
+#include "chrome/browser/search/search.h"
+#include "chrome/browser/ui/browser_instant_controller.h"
+#include "chrome/browser/ui/tabs/tab_strip_model.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/common/url_constants.h"
+#include "content/public/browser/navigation_controller.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+#include "content/public/browser/web_contents_observer.h"
+
+namespace chrome {
+
+namespace {
+
+class BrowserInstantControllerTest : public InstantUnitTestBase {
+ protected:
+  friend class FakeWebContentsObserver;
+};
+
+const struct TabReloadTestCase {
+  const char* description;
+  const char* start_url;
+  bool start_in_instant_process;
+  bool should_reload;
+  bool end_in_instant_process;
+} kTabReloadTestCases[] = {
+    {"Local Embedded NTP", chrome::kChromeSearchLocalNtpUrl,
+     true, true, true},
+    {"Remote Embedded NTP", "https://www.google.com/instant?strk",
+     true, true, false},
+    {"Remote Embedded SERP", "https://www.google.com/url?strk&bar=search+terms",
+     true, true, false},
+    {"Other NTP", "https://bar.com/instant?strk",
+     false, false, false}
+};
+
+class FakeWebContentsObserver : public content::WebContentsObserver {
+ public:
+  FakeWebContentsObserver(BrowserInstantControllerTest* base_test,
+                          content::WebContents* contents)
+      : WebContentsObserver(contents),
+        contents_(contents),
+        base_test_(base_test),
+        url_(contents->GetURL()),
+        num_reloads_(0) {}
+
+  virtual void NavigateToPendingEntry(
+      const GURL& url,
+      content::NavigationController::ReloadType reload_type) OVERRIDE {
+    // The tab reload event doesn't work with BrowserWithTestWindowTest.
+    // So we capture the NavigateToPendingEntry, and use the
+    // BrowserWithTestWindowTest::NavigateAndCommit to simulate the complete
+    // reload. Note that this will again trigger NavigateToPendingEntry, so we
+    // remove this as observer.
+    content::NavigationController* controller =
+        &web_contents()->GetController();
+    Observe(NULL);
+
+    if (url_ == url)
+      num_reloads_++;
+
+    base_test_->NavigateAndCommit(controller, url);
+  }
+
+  int num_reloads() const {
+    return num_reloads_;
+  }
+
+  content::WebContents* contents() {
+    return contents_;
+  }
+
+ protected:
+  friend class BrowserInstantControllerTest;
+  FRIEND_TEST_ALL_PREFIXES(BrowserInstantControllerTest,
+                           DefaultSearchProviderChanged);
+  FRIEND_TEST_ALL_PREFIXES(BrowserInstantControllerTest,
+                           GoogleBaseURLUpdated);
+
+ private:
+  content::WebContents* contents_;
+  BrowserInstantControllerTest* base_test_;
+  const GURL& url_;
+  int num_reloads_;
+};
+
+TEST_F(BrowserInstantControllerTest, DefaultSearchProviderChanged) {
+  size_t num_tests = arraysize(kTabReloadTestCases);
+  ScopedVector<FakeWebContentsObserver> observers;
+  for (size_t i = 0; i < num_tests; ++i) {
+    const TabReloadTestCase& test = kTabReloadTestCases[i];
+    AddTab(browser(), GURL(test.start_url));
+    content::WebContents* contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+
+    // Validate initial instant state.
+    EXPECT_EQ(test.start_in_instant_process,
+        instant_service_->IsInstantProcess(
+          contents->GetRenderProcessHost()->GetID()))
+      << test.description;
+
+    // Setup an observer to verify reload or absence thereof.
+    observers.push_back(new FakeWebContentsObserver(this, contents));
+  }
+
+  SetDefaultSearchProvider("https://bar.com/");
+
+  for (size_t i = 0; i < num_tests; ++i) {
+    FakeWebContentsObserver* observer = observers[i];
+    const TabReloadTestCase& test = kTabReloadTestCases[i];
+    content::WebContents* contents = observer->contents();
+
+    // Validate final instant state.
+    EXPECT_EQ(test.end_in_instant_process,
+        instant_service_->IsInstantProcess(
+          contents->GetRenderProcessHost()->GetID()))
+      << test.description;
+
+    // Ensure only the expected tabs(contents) reloaded.
+    EXPECT_EQ(test.should_reload ? 1 : 0, observer->num_reloads())
+      << test.description;
+  }
+}
+
+TEST_F(BrowserInstantControllerTest, GoogleBaseURLUpdated) {
+  const size_t num_tests = arraysize(kTabReloadTestCases);
+  ScopedVector<FakeWebContentsObserver> observers;
+  for (size_t i = 0; i < num_tests; ++i) {
+    const TabReloadTestCase& test = kTabReloadTestCases[i];
+    AddTab(browser(), GURL(test.start_url));
+    content::WebContents* contents =
+      browser()->tab_strip_model()->GetActiveWebContents();
+
+    // Validate initial instant state.
+    EXPECT_EQ(test.start_in_instant_process,
+        instant_service_->IsInstantProcess(
+          contents->GetRenderProcessHost()->GetID()))
+      << test.description;
+
+    // Setup an observer to verify reload or absence thereof.
+    observers.push_back(new FakeWebContentsObserver(this, contents));
+  }
+
+  NotifyGoogleBaseURLUpdate("https://www.google.es/");
+
+  for (size_t i = 0; i < num_tests; ++i) {
+    const TabReloadTestCase& test = kTabReloadTestCases[i];
+    FakeWebContentsObserver* observer = observers[i];
+    content::WebContents* contents = observer->contents();
+
+    // Validate final instant state.
+    EXPECT_EQ(test.end_in_instant_process,
+        instant_service_->IsInstantProcess(
+          contents->GetRenderProcessHost()->GetID()))
+      << test.description;
+
+    // Ensure only the expected tabs(contents) reloaded.
+    EXPECT_EQ(test.should_reload ? 1 : 0, observer->num_reloads())
+      << test.description;
+  }
+}
+
+TEST_F(BrowserInstantControllerTest, BrowserWindowLifecycle) {
+  scoped_ptr<BrowserWindow> window(CreateBrowserWindow());
+  Browser::CreateParams params(profile(), chrome::HOST_DESKTOP_TYPE_NATIVE);
+  params.window = window.get();
+  scoped_ptr<Browser> browser(new Browser(params));
+  InstantServiceObserver* bic;
+  bic = browser->instant_controller();
+  EXPECT_TRUE(IsInstantServiceObserver(bic))
+    << "New BrowserInstantController should register as InstantServiceObserver";
+
+  browser.reset(NULL);
+  window.reset(NULL);
+  EXPECT_FALSE(IsInstantServiceObserver(bic))
+    << "New BrowserInstantController should register as InstantServiceObserver";
+}
+
+}  // namespace
+
+}  // namespace chrome
diff --git a/chrome/browser/ui/search/instant_extended_interactive_uitest.cc b/chrome/browser/ui/search/instant_extended_interactive_uitest.cc
index 98b3ec7..a1142c5 100644
--- a/chrome/browser/ui/search/instant_extended_interactive_uitest.cc
+++ b/chrome/browser/ui/search/instant_extended_interactive_uitest.cc
@@ -898,121 +898,6 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
   EXPECT_EQ(1, on_most_visited_change_calls_);
 }
 
-// Flaky: crbug.com/267096
-IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
-                       DISABLED_OnDefaultSearchProviderChanged) {
-  InstantService* instant_service =
-      InstantServiceFactory::GetForProfile(browser()->profile());
-  ASSERT_NE(static_cast<InstantService*>(NULL), instant_service);
-
-  // Setup Instant.
-  ASSERT_NO_FATAL_FAILURE(SetupInstant(browser()));
-  FocusOmniboxAndWaitForInstantNTPSupport();
-  EXPECT_EQ(1, instant_service->GetInstantProcessCount());
-
-  // Navigating to the NTP should use the Instant render process.
-  content::WindowedNotificationObserver new_tab_observer(
-      content::NOTIFICATION_NAV_ENTRY_COMMITTED,
-      content::NotificationService::AllSources());
-  ui_test_utils::NavigateToURLWithDisposition(
-      browser(),
-      GURL(chrome::kChromeUINewTabURL),
-      CURRENT_TAB,
-      ui_test_utils::BROWSER_TEST_NONE);
-  new_tab_observer.Wait();
-
-  content::WebContents* ntp_contents =
-      browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_TRUE(chrome::IsInstantNTP(ntp_contents));
-  EXPECT_TRUE(instant_service->IsInstantProcess(
-      ntp_contents->GetRenderProcessHost()->GetID()));
-  GURL ntp_url = ntp_contents->GetURL();
-
-  AddBlankTabAndShow(browser());
-  content::WebContents* active_tab =
-      browser()->tab_strip_model()->GetActiveWebContents();
-  EXPECT_FALSE(chrome::IsInstantNTP(active_tab));
-  EXPECT_FALSE(instant_service->IsInstantProcess(
-      active_tab->GetRenderProcessHost()->GetID()));
-
-  TemplateURLData data;
-  data.short_name = ASCIIToUTF16("t");
-  data.SetURL("http://defaultturl/q={searchTerms}");
-  data.suggestions_url = "http://defaultturl2/q={searchTerms}";
-  data.instant_url = "http://does/not/exist";
-  data.alternate_urls.push_back(data.instant_url + "#q={searchTerms}");
-  data.search_terms_replacement_key = "strk";
-
-  TemplateURL* template_url = new TemplateURL(browser()->profile(), data);
-  TemplateURLService* service =
-      TemplateURLServiceFactory::GetForProfile(browser()->profile());
-  ui_test_utils::WaitForTemplateURLServiceToLoad(service);
-  service->Add(template_url);  // Takes ownership of |template_url|.
-
-  // Change the default search provider.
-  content::WindowedNotificationObserver observer(
-      content::NOTIFICATION_LOAD_STOP,
-      content::Source<content::NavigationController>(
-          &ntp_contents->GetController()));
-  service->SetDefaultSearchProvider(template_url);
-  observer.Wait();
-
-  // |ntp_contents| should not use the Instant render process.
-  EXPECT_FALSE(chrome::IsInstantNTP(ntp_contents));
-  EXPECT_FALSE(instant_service->IsInstantProcess(
-      ntp_contents->GetRenderProcessHost()->GetID()));
-  // Make sure the URL remains the same.
-  EXPECT_EQ(ntp_url, ntp_contents->GetURL());
-}
-
-IN_PROC_BROWSER_TEST_F(InstantExtendedTest,
-                       ReloadLocalNTPOnSearchProviderChange) {
-  // Setup Instant.
-  ASSERT_NO_FATAL_FAILURE(SetupInstant(browser()));
-  FocusOmniboxAndWaitForInstantNTPSupport();
-
-  // Navigate to Local NTP.
-  content::WindowedNotificationObserver new_tab_observer(
-      content::NOTIFICATION_NAV_ENTRY_COMMITTED,
-      content::NotificationService::AllSources());
-  ui_test_utils::NavigateToURLWithDisposition(
-      browser(),
-      GURL(chrome::kChromeSearchLocalNtpUrl),
-      CURRENT_TAB,
-      ui_test_utils::BROWSER_TEST_NONE);
-  new_tab_observer.Wait();
-
-  content::WebContents* ntp_contents =
-      browser()->tab_strip_model()->GetActiveWebContents();
-  GURL ntp_url = ntp_contents->GetURL();
-
-  TemplateURLData data;
-  data.short_name = ASCIIToUTF16("t");
-  data.SetURL("http://defaultturl/q={searchTerms}");
-  data.suggestions_url = "http://defaultturl2/q={searchTerms}";
-  data.instant_url = "http://does/not/exist";
-  data.alternate_urls.push_back(data.instant_url + "#q={searchTerms}");
-  data.search_terms_replacement_key = "strk";
-
-  TemplateURL* template_url = new TemplateURL(browser()->profile(), data);
-  TemplateURLService* service =
-      TemplateURLServiceFactory::GetForProfile(browser()->profile());
-  ui_test_utils::WaitForTemplateURLServiceToLoad(service);
-  service->Add(template_url);  // Takes ownership of |template_url|.
-
-  // Change the default search provider. This will reload the local NTP and the
-  // page URL will remain the same.
-  content::WindowedNotificationObserver observer(
-      content::NOTIFICATION_LOAD_STOP,
-      content::Source<content::NavigationController>(
-          &ntp_contents->GetController()));
-  service->SetDefaultSearchProvider(template_url);
-  observer.Wait();
-
-  // Make sure the URL remains the same.
-  EXPECT_EQ(ntp_url, ntp_contents->GetURL());
-}
-
 IN_PROC_BROWSER_TEST_F(InstantExtendedPrefetchTest, SetPrefetchQuery) {
   ASSERT_NO_FATAL_FAILURE(SetupInstant(browser()));
   FocusOmniboxAndWaitForInstantNTPSupport();
diff --git a/chrome/browser/ui/search/instant_extended_manual_interactive_uitest.cc b/chrome/browser/ui/search/instant_extended_manual_interactive_uitest.cc
index af3206f..0cc5290 100644
--- a/chrome/browser/ui/search/instant_extended_manual_interactive_uitest.cc
+++ b/chrome/browser/ui/search/instant_extended_manual_interactive_uitest.cc
@@ -98,7 +98,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedManualTest, MANUAL_ShowsGoogleNTP) {
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(browser()->profile());
   ASSERT_NE(static_cast<InstantService*>(NULL), instant_service);
-  instant_service->ntp_prerenderer()->ReloadStaleNTP();
+  instant_service->ntp_prerenderer()->ReloadInstantNTP();
 
   FocusOmniboxAndWaitForInstantNTPSupport();
   content::WindowedNotificationObserver observer(
@@ -120,7 +120,7 @@ IN_PROC_BROWSER_TEST_F(InstantExtendedManualTest, MANUAL_SearchesFromFakebox) {
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(browser()->profile());
   ASSERT_NE(static_cast<InstantService*>(NULL), instant_service);
-  instant_service->ntp_prerenderer()->ReloadStaleNTP();
+  instant_service->ntp_prerenderer()->ReloadInstantNTP();
 
   FocusOmniboxAndWaitForInstantNTPSupport();
   // Open a new tab page.
diff --git a/chrome/browser/ui/search/instant_ntp_prerenderer.cc b/chrome/browser/ui/search/instant_ntp_prerenderer.cc
index 7b3957a..d25c0c0 100644
--- a/chrome/browser/ui/search/instant_ntp_prerenderer.cc
+++ b/chrome/browser/ui/search/instant_ntp_prerenderer.cc
@@ -45,6 +45,7 @@ void DeleteNTPSoon(scoped_ptr<InstantNTP> ntp) {
 
 
 InstantNTPPrerenderer::InstantNTPPrerenderer(Profile* profile,
+                                             InstantService* instant_service,
                                              PrefService* prefs)
     : profile_(profile) {
   DCHECK(profile);
@@ -54,23 +55,26 @@ InstantNTPPrerenderer::InstantNTPPrerenderer(Profile* profile,
     profile_pref_registrar_.Init(prefs);
     profile_pref_registrar_.Add(
         prefs::kSearchSuggestEnabled,
-        base::Bind(&InstantNTPPrerenderer::ReloadStaleNTP,
-                   base::Unretained(this)));
-    profile_pref_registrar_.Add(
-        prefs::kDefaultSearchProviderID,
-        base::Bind(&InstantNTPPrerenderer::OnDefaultSearchProviderChanged,
+        base::Bind(&InstantNTPPrerenderer::ReloadInstantNTP,
                    base::Unretained(this)));
   }
   net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
+
+  // Allow instant_service to be null for unit tets.
+  if (instant_service)
+    instant_service->AddObserver(this);
 }
 
 InstantNTPPrerenderer::~InstantNTPPrerenderer() {
+  InstantService* instant_service =
+      InstantServiceFactory::GetForProfile(profile_);
+  if (instant_service)
+    instant_service->RemoveObserver(this);
   net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
 }
 
-void InstantNTPPrerenderer::PreloadInstantNTP() {
-  DCHECK(!ntp());
-  ReloadStaleNTP();
+void InstantNTPPrerenderer::ReloadInstantNTP() {
+  ResetNTP(GetInstantURL());
 }
 
 scoped_ptr<content::WebContents> InstantNTPPrerenderer::ReleaseNTPContents() {
@@ -84,7 +88,7 @@ scoped_ptr<content::WebContents> InstantNTPPrerenderer::ReleaseNTPContents() {
   scoped_ptr<content::WebContents> ntp_contents = ntp_->ReleaseContents();
 
   // Preload a new InstantNTP.
-  ResetNTP(GetInstantURL());
+  ReloadInstantNTP();
   return ntp_contents.Pass();
 }
 
@@ -175,7 +179,7 @@ void InstantNTPPrerenderer::OnNetworkChanged(
     return;
 
   if (!ntp() || ntp()->IsLocal())
-    ResetNTP(GetInstantURL());
+    ReloadInstantNTP();
 }
 
 void InstantNTPPrerenderer::InstantSupportDetermined(
@@ -245,28 +249,15 @@ void InstantNTPPrerenderer::InstantPageLoadFailed(
     ResetNTP(GetLocalInstantURL());
 }
 
-void InstantNTPPrerenderer::OnDefaultSearchProviderChanged(
-    const std::string& pref_name) {
-  DCHECK_EQ(pref_name, std::string(prefs::kDefaultSearchProviderID));
-  if (!ntp())
-    return;
-
-  ResetNTP(GetInstantURL());
-}
-
 void InstantNTPPrerenderer::ResetNTP(const std::string& instant_url) {
   // Instant NTP is only used in extended mode so we should always have a
   // non-empty URL to use.
   DCHECK(!instant_url.empty());
   ntp_.reset(new InstantNTP(this, instant_url, profile_));
-  ntp_->InitContents(base::Bind(&InstantNTPPrerenderer::ReloadStaleNTP,
+  ntp_->InitContents(base::Bind(&InstantNTPPrerenderer::ReloadInstantNTP,
                                 base::Unretained(this)));
 }
 
-void InstantNTPPrerenderer::ReloadStaleNTP() {
-  ResetNTP(GetInstantURL());
-}
-
 bool InstantNTPPrerenderer::PageIsCurrent() const {
   const std::string& instant_url = GetInstantURL();
   if (instant_url.empty() ||
@@ -298,3 +289,11 @@ bool InstantNTPPrerenderer::ShouldSwitchToLocalNTP() const {
   // (unless the finch flag to use the remote NTP is set).
   return !(InStartup() && chrome::ShouldPreferRemoteNTPOnStartup());
 }
+
+void InstantNTPPrerenderer::DefaultSearchProviderChanged() {
+  ReloadInstantNTP();
+}
+
+void InstantNTPPrerenderer::GoogleURLUpdated() {
+  ReloadInstantNTP();
+}
diff --git a/chrome/browser/ui/search/instant_ntp_prerenderer.h b/chrome/browser/ui/search/instant_ntp_prerenderer.h
index 933e0a8..10d3292 100644
--- a/chrome/browser/ui/search/instant_ntp_prerenderer.h
+++ b/chrome/browser/ui/search/instant_ntp_prerenderer.h
@@ -11,14 +11,14 @@
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_change_registrar.h"
+#include "chrome/browser/search/instant_service_observer.h"
 #include "chrome/browser/ui/search/instant_page.h"
 #include "content/public/browser/web_contents.h"
 #include "net/base/network_change_notifier.h"
 
-class InstantExtendedTest;
 class InstantNTP;
 class InstantService;
-class InstantTestBase;
+class PrefService;
 class Profile;
 
 // InstantNTPPrerenderer maintains a prerendered instance of InstantNTP.
@@ -31,13 +31,15 @@ class Profile;
 // InstantNTPPrerenderer is owned by InstantService.
 class InstantNTPPrerenderer
     : public InstantPage::Delegate,
-      public net::NetworkChangeNotifier::NetworkChangeObserver {
+      public net::NetworkChangeNotifier::NetworkChangeObserver,
+      public InstantServiceObserver {
  public:
-  InstantNTPPrerenderer(Profile* profile, PrefService* prefs);
+  InstantNTPPrerenderer(Profile* profile, InstantService* instant_service,
+      PrefService* prefs);
   virtual ~InstantNTPPrerenderer();
 
   // Preloads |ntp_| with a new InstantNTP.
-  void PreloadInstantNTP();
+  void ReloadInstantNTP();
 
   // Releases and returns the InstantNTP WebContents. May be NULL. Loads a new
   // WebContents for the InstantNTP.
@@ -137,16 +139,13 @@ class InstantNTPPrerenderer
   virtual void UndoAllMostVisitedDeletions() OVERRIDE;
   virtual void InstantPageLoadFailed(content::WebContents* contents) OVERRIDE;
 
-  // Called when the default search provider changes. Resets InstantNTP.
-  void OnDefaultSearchProviderChanged(const std::string& pref_name);
+  // Overridden from InstantServiceObserver:
+  virtual void DefaultSearchProviderChanged() OVERRIDE;
+  virtual void GoogleURLUpdated() OVERRIDE;
 
   // Recreates |ntp_| using |instant_url|.
   void ResetNTP(const std::string& instant_url);
 
-  // Resets |ntp_| with a new InstantNTP. Called when |ntp_| is stale or when a
-  // pref is changed.
-  void ReloadStaleNTP();
-
   // Returns true if |ntp_| has an up-to-date Instant URL and supports Instant.
   // Note that local URLs will not pass this check.
   bool PageIsCurrent() const;
diff --git a/chrome/browser/ui/search/instant_ntp_prerenderer_unittest.cc b/chrome/browser/ui/search/instant_ntp_prerenderer_unittest.cc
index 917e01a..c3899b7f 100644
--- a/chrome/browser/ui/search/instant_ntp_prerenderer_unittest.cc
+++ b/chrome/browser/ui/search/instant_ntp_prerenderer_unittest.cc
@@ -3,11 +3,9 @@
 // found in the LICENSE file.
 
 #include "base/memory/scoped_ptr.h"
-#include "base/metrics/histogram.h"
-#include "base/metrics/histogram_samples.h"
-#include "base/metrics/statistics_recorder.h"
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
+#include "chrome/browser/search/instant_service_factory.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/ui/search/instant_ntp.h"
 #include "chrome/browser/ui/search/instant_ntp_prerenderer.h"
@@ -17,10 +15,6 @@
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using base::HistogramBase;
-using base::HistogramSamples;
-using base::StatisticsRecorder;
-
 class TestableInstantNTP : public InstantNTP {
  public:
   TestableInstantNTP(InstantNTPPrerenderer* ntp_prerenderer,
@@ -62,13 +56,15 @@ class TestableInstantNTP : public InstantNTP {
 
 class TestableInstantNTPPrerenderer : public InstantNTPPrerenderer {
  public:
-  explicit TestableInstantNTPPrerenderer(TestingProfile* profile)
-      : InstantNTPPrerenderer(profile, NULL),
+  explicit TestableInstantNTPPrerenderer(TestingProfile* profile,
+      InstantService* instant_service)
+      : InstantNTPPrerenderer(profile, instant_service, NULL),
         test_instant_url_("http://test_url"),
         override_javascript_enabled_(true),
         test_javascript_enabled_(true),
         test_in_startup_(false),
-        test_ntp_(NULL) {}
+        test_ntp_(NULL) {
+  }
 
   // Overrides from InstantNTPPrerenderer
   virtual std::string GetInstantURL() const OVERRIDE {
@@ -125,10 +121,15 @@ private:
 
 class InstantNTPPrerendererTest : public testing::Test {
  public:
-  InstantNTPPrerendererTest()
-      : instant_ntp_prerenderer_(new TestableInstantNTPPrerenderer(&profile_)) {
-    base::StatisticsRecorder::Initialize();
+  virtual void SetUp() OVERRIDE {
     chrome::EnableInstantExtendedAPIForTesting();
+    instant_service_ = InstantServiceFactory::GetForProfile(&profile_);
+    instant_ntp_prerenderer_.reset(
+        new TestableInstantNTPPrerenderer(&profile_, instant_service_));
+  }
+
+  virtual void TearDown() OVERRIDE {
+    instant_ntp_prerenderer_.reset();
   }
 
   TestableInstantNTPPrerenderer* instant_ntp_prerenderer() {
@@ -142,6 +143,7 @@ class InstantNTPPrerendererTest : public testing::Test {
  private:
   content::TestBrowserThreadBundle thread_bundle_;
   scoped_ptr<TestableInstantNTPPrerenderer> instant_ntp_prerenderer_;
+  InstantService* instant_service_;
   mutable TestingProfile profile_;
 };
 
diff --git a/chrome/browser/ui/search/instant_test_utils.cc b/chrome/browser/ui/search/instant_test_utils.cc
index 67d1d19..c576e37 100644
--- a/chrome/browser/ui/search/instant_test_utils.cc
+++ b/chrome/browser/ui/search/instant_test_utils.cc
@@ -61,7 +61,7 @@ void InstantTestBase::SetupInstant(Browser* browser) {
   InstantService* instant_service =
       InstantServiceFactory::GetForProfile(browser_->profile());
   ASSERT_NE(static_cast<InstantService*>(NULL), instant_service);
-  instant_service->ntp_prerenderer()->ReloadStaleNTP();
+  instant_service->ntp_prerenderer()->ReloadInstantNTP();
 }
 
 void InstantTestBase::SetInstantURL(const std::string& url) {
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index b301980..ecd7a79 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1874,6 +1874,7 @@
         'browser/search/instant_service.h',
         'browser/search/instant_service_factory.cc',
         'browser/search/instant_service_factory.h',
+        'browser/search/instant_service_observer.cc',
         'browser/search/instant_service_observer.h',
         'browser/search/local_ntp_source.cc',
         'browser/search/local_ntp_source.h',
diff --git a/chrome/chrome_tests_unit.gypi b/chrome/chrome_tests_unit.gypi
index 1ef8680..04d0ddd 100644
--- a/chrome/chrome_tests_unit.gypi
+++ b/chrome/chrome_tests_unit.gypi
@@ -1173,6 +1173,9 @@
         'browser/safe_browsing/signature_util_win_unittest.cc',
         'browser/safe_browsing/two_phase_uploader_unittest.cc',
         'browser/search/iframe_source_unittest.cc',
+        'browser/search/instant_service_unittest.cc',
+        'browser/search/instant_unittest_base.cc',
+        'browser/search/instant_unittest_base.h',
         'browser/search/most_visited_iframe_source_unittest.cc',
         'browser/search/search_unittest.cc',
         'browser/search_engines/search_host_to_urls_map_unittest.cc',
@@ -1399,6 +1402,7 @@
         'browser/ui/bookmarks/bookmark_unittest.cc',
         'browser/ui/bookmarks/recently_used_folders_combo_model_unittest.cc',
         'browser/ui/browser_command_controller_unittest.cc',
+        'browser/ui/browser_instant_controller_unittest.cc',
         'browser/ui/browser_iterator_unittest.cc',
         'browser/ui/browser_unittest.cc',
         'browser/ui/chrome_select_file_policy_unittest.cc',
@@ -2501,12 +2505,14 @@
             'browser/profiles/off_the_record_profile_impl_unittest.cc',
             'browser/profiles/profile_list_desktop_unittest.cc',
             'browser/profiles/profile_loader_unittest.cc',
+            'browser/search/instant_service_unittest.cc',
             'browser/search/search_unittest.cc',
             'browser/signin/profile_oauth2_token_service_unittest.cc',
             'browser/sync/profile_sync_service_session_unittest.cc',
             'browser/sync/sync_global_error_unittest.cc',
             'browser/tab_contents/render_view_context_menu_unittest.cc',
             'browser/ui/autofill/autofill_dialog_controller_unittest.cc',
+            'browser/ui/browser_instant_controller_unittest.cc',
             'browser/ui/bookmarks/bookmark_bubble_sign_in_delegate_unittest.cc',
             'browser/ui/bookmarks/bookmark_context_menu_controller_unittest.cc',
             'browser/ui/bookmarks/bookmark_prompt_controller_unittest.cc',