1. Renamed {google:instantEnabledParameter} to {google:forceInstantResults}.

2. Added |force_instant_results| param to GetInstantURL() to append {google:forceInstantResults} to Instant URL.
3. Wrote a unit test for GetInstantURL(). 
4. Added a member variable in struct SearchTermsArgs.
5. Added |force_instant_results| param to SearchTermsData::forceInstantResultsParam().

BUG=269186
TEST=none

Review URL: https://codereview.chromium.org/35373005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231689 0039d316-1c4b-4281-b951-d872f2087c98

13 files changed, 102 insertions, 57 deletions

diff --git a/chrome/browser/autocomplete/history_url_provider.cc b/chrome/browser/autocomplete/history_url_provider.cc
index 0ff6b50..789a3a5 100644
--- a/chrome/browser/autocomplete/history_url_provider.cc
+++ b/chrome/browser/autocomplete/history_url_provider.cc
@@ -204,7 +204,8 @@ class SearchTermsDataSnapshot : public SearchTermsData {
   virtual std::string GetApplicationLocale() const OVERRIDE;
   virtual string16 GetRlzParameterValue() const OVERRIDE;
   virtual std::string GetSearchClient() const OVERRIDE;
-  virtual std::string InstantEnabledParam() const OVERRIDE;
+  virtual std::string ForceInstantResultsParam(
+      bool for_prerender) const OVERRIDE;
   virtual std::string InstantExtendedEnabledParam() const OVERRIDE;
   virtual std::string NTPIsThemedParam() const OVERRIDE;
 
@@ -213,7 +214,7 @@ class SearchTermsDataSnapshot : public SearchTermsData {
   std::string application_locale_;
   string16 rlz_parameter_value_;
   std::string search_client_;
-  std::string instant_enabled_param_;
+  std::string force_instant_results_param_;
   std::string instant_extended_enabled_param_;
   std::string ntp_is_themed_param_;
 
@@ -226,7 +227,8 @@ SearchTermsDataSnapshot::SearchTermsDataSnapshot(
       application_locale_(search_terms_data.GetApplicationLocale()),
       rlz_parameter_value_(search_terms_data.GetRlzParameterValue()),
       search_client_(search_terms_data.GetSearchClient()),
-      instant_enabled_param_(search_terms_data.InstantEnabledParam()),
+      force_instant_results_param_(
+          search_terms_data.ForceInstantResultsParam(false)),
       instant_extended_enabled_param_(
           search_terms_data.InstantExtendedEnabledParam()),
       ntp_is_themed_param_(search_terms_data.NTPIsThemedParam()) {}
@@ -250,8 +252,9 @@ std::string SearchTermsDataSnapshot::GetSearchClient() const {
   return search_client_;
 }
 
-std::string SearchTermsDataSnapshot::InstantEnabledParam() const {
-  return instant_enabled_param_;
+std::string SearchTermsDataSnapshot::ForceInstantResultsParam(
+    bool for_prerender) const {
+  return force_instant_results_param_;
 }
 
 std::string SearchTermsDataSnapshot::InstantExtendedEnabledParam() const {
diff --git a/chrome/browser/search/search.cc b/chrome/browser/search/search.cc
index c063cbc..60498e3 100644
--- a/chrome/browser/search/search.cc
+++ b/chrome/browser/search/search.cc
@@ -128,17 +128,20 @@ TemplateURL* GetDefaultSearchProviderTemplateURL(Profile* profile) {
 
 GURL TemplateURLRefToGURL(const TemplateURLRef& ref,
                           int start_margin,
-                          bool append_extra_query_params) {
+                          bool append_extra_query_params,
+                          bool force_instant_results) {
   TemplateURLRef::SearchTermsArgs search_terms_args =
       TemplateURLRef::SearchTermsArgs(string16());
   search_terms_args.omnibox_start_margin = start_margin;
   search_terms_args.append_extra_query_params = append_extra_query_params;
+  search_terms_args.force_instant_results = force_instant_results;
   return GURL(ref.ReplaceSearchTerms(search_terms_args));
 }
 
 bool MatchesAnySearchURL(const GURL& url, TemplateURL* template_url) {
   GURL search_url =
-      TemplateURLRefToGURL(template_url->url_ref(), kDisableStartMargin, false);
+      TemplateURLRefToGURL(template_url->url_ref(), kDisableStartMargin, false,
+                           false);
   if (search_url.is_valid() &&
       search::MatchesOriginAndPath(url, search_url))
     return true;
@@ -146,7 +149,7 @@ bool MatchesAnySearchURL(const GURL& url, TemplateURL* template_url) {
   // "URLCount() - 1" because we already tested url_ref above.
   for (size_t i = 0; i < template_url->URLCount() - 1; ++i) {
     TemplateURLRef ref(template_url, i);
-    search_url = TemplateURLRefToGURL(ref, kDisableStartMargin, false);
+    search_url = TemplateURLRefToGURL(ref, kDisableStartMargin, false, false);
     if (search_url.is_valid() &&
         search::MatchesOriginAndPath(url, search_url))
       return true;
@@ -223,7 +226,7 @@ bool IsInstantURL(const GURL& url, Profile* profile) {
 
   const TemplateURLRef& instant_url_ref = template_url->instant_url_ref();
   const GURL instant_url =
-      TemplateURLRefToGURL(instant_url_ref, kDisableStartMargin, false);
+      TemplateURLRefToGURL(instant_url_ref, kDisableStartMargin, false, false);
   if (!instant_url.is_valid())
     return false;
 
@@ -422,7 +425,8 @@ bool IsSuggestPrefEnabled(Profile* profile) {
          profile->GetPrefs()->GetBoolean(prefs::kSearchSuggestEnabled);
 }
 
-GURL GetInstantURL(Profile* profile, int start_margin) {
+GURL GetInstantURL(Profile* profile, int start_margin,
+                   bool force_instant_results) {
   if (!IsInstantExtendedAPIEnabled() || !IsSuggestPrefEnabled(profile))
     return GURL();
 
@@ -431,7 +435,8 @@ GURL GetInstantURL(Profile* profile, int start_margin) {
     return GURL();
 
   GURL instant_url =
-      TemplateURLRefToGURL(template_url->instant_url_ref(), start_margin, true);
+      TemplateURLRefToGURL(template_url->instant_url_ref(), start_margin, true,
+                           force_instant_results);
   if (!instant_url.is_valid() ||
       !template_url->HasSearchTermsReplacementKey(instant_url))
     return GURL();
@@ -461,7 +466,8 @@ std::vector<GURL> GetSearchURLs(Profile* profile) {
     return result;
   for (size_t i = 0; i < template_url->URLCount(); ++i) {
     TemplateURLRef ref(template_url, i);
-    result.push_back(TemplateURLRefToGURL(ref, kDisableStartMargin, false));
+    result.push_back(TemplateURLRefToGURL(ref, kDisableStartMargin, false,
+                                          false));
   }
   return result;
 }
@@ -481,7 +487,7 @@ GURL GetNewTabPageURL(Profile* profile) {
     return GURL(chrome::kChromeSearchLocalNtpUrl);
 
   GURL url(TemplateURLRefToGURL(template_url->new_tab_url_ref(),
-                                kDisableStartMargin, false));
+                                kDisableStartMargin, false, false));
   if (!url.is_valid() || !url.SchemeIsSecure())
     return GURL(chrome::kChromeSearchLocalNtpUrl);
 
@@ -588,7 +594,7 @@ GURL GetEffectiveURLForInstant(const GURL& url, Profile* profile) {
   TemplateURL* template_url = GetDefaultSearchProviderTemplateURL(profile);
   if (template_url) {
     const GURL instant_url = TemplateURLRefToGURL(
-        template_url->instant_url_ref(), kDisableStartMargin, false);
+        template_url->instant_url_ref(), kDisableStartMargin, false, false);
     if (instant_url.is_valid() &&
         search::MatchesOriginAndPath(url, instant_url)) {
       replacements.SetHost(online_ntp_host.c_str(),
diff --git a/chrome/browser/search/search.h b/chrome/browser/search/search.h
index 5f2eee5..dd1904f 100644
--- a/chrome/browser/search/search.h
+++ b/chrome/browser/search/search.h
@@ -107,11 +107,15 @@ bool NavEntryIsInstantNTP(const content::WebContents* contents,
 // because it doesn't satisfy the requirements for extended mode or if Instant
 // is disabled through preferences). Callers must check that the returned URL is
 // valid before using it. The value of |start_margin| is used for the "es_sm"
-// parameter in the URL.
+// parameter in the URL. |force_instant_results| forces a search page to update
+// results incrementally even if that is otherwise disabled by google.com
+// preferences.
 // NOTE: This method expands the default search engine's instant_url template,
 // so it shouldn't be called from SearchTermsData or other such code that would
 // lead to an infinite recursion.
-GURL GetInstantURL(Profile* profile, int start_margin);
+GURL GetInstantURL(Profile* profile,
+                   int start_margin,
+                   bool force_instant_results);
 
 // Returns URLs associated with the default search engine for |profile|.
 std::vector<GURL> GetSearchURLs(Profile* profile);
diff --git a/chrome/browser/search/search_unittest.cc b/chrome/browser/search/search_unittest.cc
index af006e6..3afc595 100644
--- a/chrome/browser/search/search_unittest.cc
+++ b/chrome/browser/search/search_unittest.cc
@@ -341,7 +341,8 @@ class SearchTest : public BrowserWithTestWindowTest {
     TemplateURLData data;
     data.SetURL("http://foo.com/url?bar={searchTerms}");
     data.instant_url = "http://foo.com/instant?"
-        "{google:omniboxStartMarginParameter}foo=foo#foo=foo&strk";
+        "{google:omniboxStartMarginParameter}{google:forceInstantResults}"
+        "foo=foo#foo=foo&strk";
     if (set_ntp_url) {
       data.new_tab_url = (insecure_ntp_url ? "http" : "https") +
           std::string("://foo.com/newtab?strk");
@@ -709,7 +710,8 @@ TEST_F(SearchTest, InstantCacheableNTPNavigationEntry) {
   EXPECT_TRUE(NavEntryIsInstantNTP(contents,
                                    controller.GetLastCommittedEntry()));
   // Instant page is not cacheable NTP.
-  NavigateAndCommitActiveTab(GetInstantURL(profile(), kDisableStartMargin));
+  NavigateAndCommitActiveTab(GetInstantURL(profile(), kDisableStartMargin,
+                                           false));
   EXPECT_FALSE(NavEntryIsInstantNTP(contents,
                                     controller.GetLastCommittedEntry()));
   // Test Cacheable NTP
@@ -762,49 +764,63 @@ TEST_F(SearchTest, UseLocalNTPIfNTPURLIsBlockedForSupervisedUser) {
 
   EXPECT_EQ(GURL(chrome::kChromeSearchLocalNtpUrl),
             chrome::GetNewTabPageURL(profile()));
-  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin));
+  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin, false));
 }
 
 TEST_F(SearchTest, GetInstantURLExtendedEnabled) {
   // Instant is disabled, so no Instant URL.
-  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin));
+  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin, false));
 
   // Enable Instant. Still no Instant URL because "strk" is missing.
   EnableInstantExtendedAPIForTesting();
   SetDefaultInstantTemplateUrl(false);
-  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin));
+  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin, false));
 
   // Set an Instant URL with a valid search terms replacement key.
   SetDefaultInstantTemplateUrl(true);
 
   // Now there should be a valid Instant URL. Note the HTTPS "upgrade".
   EXPECT_EQ(GURL("https://foo.com/instant?foo=foo#foo=foo&strk"),
-            GetInstantURL(profile(), kDisableStartMargin));
+            GetInstantURL(profile(), kDisableStartMargin, false));
 
   // Enable suggest. No difference.
   profile()->GetPrefs()->SetBoolean(prefs::kSearchSuggestEnabled, true);
   EXPECT_EQ(GURL("https://foo.com/instant?foo=foo#foo=foo&strk"),
-            GetInstantURL(profile(), kDisableStartMargin));
+            GetInstantURL(profile(), kDisableStartMargin, false));
 
   // Disable suggest. No Instant URL.
   profile()->GetPrefs()->SetBoolean(prefs::kSearchSuggestEnabled, false);
-  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin));
+  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin, false));
 }
 
 TEST_F(SearchTest, StartMarginCGI) {
   // Instant is disabled, so no Instant URL.
-  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin));
+  EXPECT_EQ(GURL(), GetInstantURL(profile(), kDisableStartMargin, false));
 
   // Enable Instant. No margin.
   EnableInstantExtendedAPIForTesting();
   profile()->GetPrefs()->SetBoolean(prefs::kSearchSuggestEnabled, true);
 
   EXPECT_EQ(GURL("https://foo.com/instant?foo=foo#foo=foo&strk"),
-            GetInstantURL(profile(), kDisableStartMargin));
+            GetInstantURL(profile(), kDisableStartMargin, false));
 
   // With start margin.
   EXPECT_EQ(GURL("https://foo.com/instant?es_sm=10&foo=foo#foo=foo&strk"),
-            GetInstantURL(profile(), 10));
+            GetInstantURL(profile(), 10, false));
+}
+
+TEST_F(SearchTest, InstantSearchEnabledCGI) {
+  EnableInstantExtendedAPIForTesting();
+
+  // Disable Instant Search.
+  // Make sure {google:forceInstantResults} is not set in the Instant URL.
+  EXPECT_EQ(GURL("https://foo.com/instant?foo=foo#foo=foo&strk"),
+            GetInstantURL(profile(), kDisableStartMargin, false));
+
+  // Enable Instant Search.
+  // Make sure {google:forceInstantResults} is set in the Instant URL.
+  EXPECT_EQ(GURL("https://foo.com/instant?ion=1&foo=foo#foo=foo&strk"),
+            GetInstantURL(profile(), kDisableStartMargin, true));
 }
 
 TEST_F(SearchTest, CommandLineOverrides) {
@@ -827,7 +843,7 @@ TEST_F(SearchTest, CommandLineOverrides) {
   // By default, Instant Extended forces the instant URL to be HTTPS, so even if
   // we set a Google base URL that is HTTP, we should get an HTTPS URL.
   UIThreadSearchTermsData::SetGoogleBaseURL("http://www.foo.com/");
-  GURL instant_url(GetInstantURL(profile(), kDisableStartMargin));
+  GURL instant_url(GetInstantURL(profile(), kDisableStartMargin, false));
   ASSERT_TRUE(instant_url.is_valid());
   EXPECT_EQ("https://www.foo.com/webhp?strk", instant_url.spec());
 
@@ -836,7 +852,7 @@ TEST_F(SearchTest, CommandLineOverrides) {
   UIThreadSearchTermsData::SetGoogleBaseURL(std::string());
   CommandLine::ForCurrentProcess()->AppendSwitchASCII(switches::kGoogleBaseURL,
                                                       "http://www.bar.com/");
-  instant_url = GetInstantURL(profile(), kDisableStartMargin);
+  instant_url = GetInstantURL(profile(), kDisableStartMargin, false);
   ASSERT_TRUE(instant_url.is_valid());
   EXPECT_EQ("http://www.bar.com/webhp?strk", instant_url.spec());
 
@@ -850,7 +866,7 @@ TEST_F(SearchTest, CommandLineOverrides) {
   // query portion of the instant URL.
   CommandLine::ForCurrentProcess()->AppendSwitchASCII(
       switches::kExtraSearchQueryParams, "a=b");
-  instant_url = GetInstantURL(profile(), kDisableStartMargin);
+  instant_url = GetInstantURL(profile(), kDisableStartMargin, false);
   ASSERT_TRUE(instant_url.is_valid());
   EXPECT_EQ("http://www.bar.com/webhp?a=b&strk", instant_url.spec());
 }
@@ -909,7 +925,7 @@ TEST_F(SearchTest, IsNTPURL) {
   // Enable Instant. No margin.
   EnableInstantExtendedAPIForTesting();
   profile()->GetPrefs()->SetBoolean(prefs::kSearchSuggestEnabled, true);
-  GURL remote_ntp_url(GetInstantURL(profile(), kDisableStartMargin));
+  GURL remote_ntp_url(GetInstantURL(profile(), kDisableStartMargin, false));
   GURL search_url_with_search_terms("https://foo.com/url?strk&bar=abc");
   GURL search_url_without_search_terms("https://foo.com/url?strk&bar");
 
diff --git a/chrome/browser/search_engines/prepopulated_engines.json b/chrome/browser/search_engines/prepopulated_engines.json
index d8d741e..e7e4db5 100644
--- a/chrome/browser/search_engines/prepopulated_engines.json
+++ b/chrome/browser/search_engines/prepopulated_engines.json
@@ -488,7 +488,7 @@
       "favicon_url": "http://www.google.com/favicon.ico",
       "search_url": "{google:baseURL}search?q={searchTerms}&{google:RLZ}{google:originalQueryForSuggestion}{google:assistedQueryStats}{google:searchFieldtrialParameter}{google:bookmarkBarPinned}{google:searchClient}{google:sourceId}{google:instantExtendedEnabledParameter}{google:omniboxStartMarginParameter}ie={inputEncoding}",
       "suggest_url": "{google:baseSuggestURL}search?{google:searchFieldtrialParameter}client={google:suggestClient}&q={searchTerms}&{google:cursorPosition}{google:zeroPrefixUrl}{google:pageClassification}sugkey={google:suggestAPIKeyParameter}",
-      "instant_url": "{google:baseURL}webhp?sourceid=chrome-instant&{google:RLZ}{google:instantEnabledParameter}{google:instantExtendedEnabledParameter}{google:ntpIsThemedParameter}{google:omniboxStartMarginParameter}ie={inputEncoding}",
+      "instant_url": "{google:baseURL}webhp?sourceid=chrome-instant&{google:RLZ}{google:forceInstantResults}{google:instantExtendedEnabledParameter}{google:ntpIsThemedParameter}{google:omniboxStartMarginParameter}ie={inputEncoding}",
       "image_url": "{google:baseURL}searchbyimage/upload",
       "new_tab_url": "{google:baseURL}_/chrome/newtab?{google:RLZ}{google:instantExtendedEnabledParameter}{google:ntpIsThemedParameter}ie={inputEncoding}",
       "image_url_post_params": "encoded_image={google:imageThumbnail},image_url={google:imageURL},sbisrc={google:imageSearchSource},original_width={google:imageOriginalWidth},original_height={google:imageOriginalHeight}",
diff --git a/chrome/browser/search_engines/search_terms_data.cc b/chrome/browser/search_engines/search_terms_data.cc
index d4af8029..34c3194 100644
--- a/chrome/browser/search_engines/search_terms_data.cc
+++ b/chrome/browser/search_engines/search_terms_data.cc
@@ -73,7 +73,8 @@ std::string SearchTermsData::GetSuggestClient() const {
   return std::string();
 }
 
-std::string SearchTermsData::InstantEnabledParam() const {
+std::string SearchTermsData::ForceInstantResultsParam(
+    bool for_prerender) const {
   return std::string();
 }
 
@@ -150,10 +151,12 @@ std::string UIThreadSearchTermsData::GetSuggestClient() const {
   return chrome::IsInstantExtendedAPIEnabled() ? "chrome-omni" : "chrome";
 }
 
-std::string UIThreadSearchTermsData::InstantEnabledParam() const {
+std::string UIThreadSearchTermsData::ForceInstantResultsParam(
+    bool for_prerender) const {
   DCHECK(!BrowserThread::IsThreadInitialized(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::UI));
-  return chrome::IsInstantExtendedAPIEnabled() ? std::string() : "ion=1&";
+  return (for_prerender || !chrome::IsInstantExtendedAPIEnabled()) ? "ion=1&" :
+      std::string();
 }
 
 std::string UIThreadSearchTermsData::InstantExtendedEnabledParam() const {
diff --git a/chrome/browser/search_engines/search_terms_data.h b/chrome/browser/search_engines/search_terms_data.h
index cbd1e7d..4980df6 100644
--- a/chrome/browser/search_engines/search_terms_data.h
+++ b/chrome/browser/search_engines/search_terms_data.h
@@ -44,14 +44,15 @@ class SearchTermsData {
   // implementation returns the empty string.
   virtual std::string GetSuggestClient() const;
 
-  // Returns a string indicating whether Instant (in the visible-preview mode)
-  // is enabled, suitable for adding as a query string param to the homepage
-  // (instant_url) request. Returns an empty string if Instant is disabled, or
-  // if it's only active in a hidden field trial mode, or if InstantExtended is
-  // enabled (since that supercedes regular Instant). Determining this requires
-  // accessing the Profile, so this can only ever be non-empty for
-  // UIThreadSearchTermsData.
-  virtual std::string InstantEnabledParam() const;
+  // Returns a string that will cause the search results page to update
+  // incrementally. Currently, Instant Extended passes a different param to
+  // search results pages that also has this effect, so by default this function
+  // returns the empty string when Instant Extended is enabled. However, when
+  // doing instant search result prerendering, we still need to pass this param,
+  // as Instant Extended does not cause incremental updates by default for the
+  // prerender page. Callers should set |for_prerender| in this case to force
+  // the returned string to be non-empty.
+  virtual std::string ForceInstantResultsParam(bool for_prerender) const;
 
   // Returns a string indicating whether InstantExtended is enabled, suitable
   // for adding as a query string param to the homepage or search requests.
@@ -74,7 +75,7 @@ class SearchTermsData {
 class UIThreadSearchTermsData : public SearchTermsData {
  public:
   // If |profile_| is NULL, the Google base URL accessors will return default
-  // values, and InstantEnabledParam(), InstantExtendedEnabledParam(), and
+  // values, and ForceInstantResultsParam(), InstantExtendedEnabledParam(), and
   // NTPIsThemedParam(), will return the empty string.
   explicit UIThreadSearchTermsData(Profile* profile);
 
@@ -83,7 +84,8 @@ class UIThreadSearchTermsData : public SearchTermsData {
   virtual string16 GetRlzParameterValue() const OVERRIDE;
   virtual std::string GetSearchClient() const OVERRIDE;
   virtual std::string GetSuggestClient() const OVERRIDE;
-  virtual std::string InstantEnabledParam() const OVERRIDE;
+  virtual std::string ForceInstantResultsParam(
+      bool for_prerender) const OVERRIDE;
   virtual std::string InstantExtendedEnabledParam() const OVERRIDE;
   virtual std::string NTPIsThemedParam() const OVERRIDE;
 
diff --git a/chrome/browser/search_engines/template_url.cc b/chrome/browser/search_engines/template_url.cc
index 6df1b6b..abe0a0f 100644
--- a/chrome/browser/search_engines/template_url.cc
+++ b/chrome/browser/search_engines/template_url.cc
@@ -66,7 +66,7 @@ const char kGoogleBaseSuggestURLParameter[] = "google:baseSuggestURL";
 const char kGoogleBaseSuggestURLParameterFull[] = "{google:baseSuggestURL}";
 const char kGoogleBookmarkBarPinnedParameter[] = "google:bookmarkBarPinned";
 const char kGoogleCursorPositionParameter[] = "google:cursorPosition";
-const char kGoogleInstantEnabledParameter[] = "google:instantEnabledParameter";
+const char kGoogleForceInstantResultsParameter[] = "google:forceInstantResults";
 const char kGoogleInstantExtendedEnabledParameter[] =
     "google:instantExtendedEnabledParameter";
 const char kGoogleInstantExtendedEnabledKey[] =
@@ -204,7 +204,8 @@ TemplateURLRef::SearchTermsArgs::SearchTermsArgs(const string16& search_terms)
       omnibox_start_margin(-1),
       page_classification(AutocompleteInput::INVALID_SPEC),
       bookmark_bar_pinned(false),
-      append_extra_query_params(false) {
+      append_extra_query_params(false),
+      force_instant_results(false) {
 }
 
 TemplateURLRef::SearchTermsArgs::~SearchTermsArgs() {
@@ -574,8 +575,8 @@ bool TemplateURLRef::ParseParameter(size_t start,
   } else if (parameter == kGoogleImageURLParameter) {
     replacements->push_back(Replacement(TemplateURLRef::GOOGLE_IMAGE_URL,
                                         start));
-  } else if (parameter == kGoogleInstantEnabledParameter) {
-    replacements->push_back(Replacement(GOOGLE_INSTANT_ENABLED, start));
+  } else if (parameter == kGoogleForceInstantResultsParameter) {
+    replacements->push_back(Replacement(GOOGLE_FORCE_INSTANT_RESULTS, start));
   } else if (parameter == kGoogleInstantExtendedEnabledParameter) {
     replacements->push_back(Replacement(GOOGLE_INSTANT_EXTENDED_ENABLED,
                                         start));
@@ -871,10 +872,13 @@ std::string TemplateURLRef::HandleReplacements(
               &url);
         break;
 
-      case GOOGLE_INSTANT_ENABLED:
+      case GOOGLE_FORCE_INSTANT_RESULTS:
         DCHECK(!i->is_post_param);
-        HandleReplacement(
-            std::string(), search_terms_data.InstantEnabledParam(), *i, &url);
+        HandleReplacement(std::string(),
+                          search_terms_data.ForceInstantResultsParam(
+                              search_terms_args.force_instant_results),
+                          *i,
+                          &url);
         break;
 
       case GOOGLE_INSTANT_EXTENDED_ENABLED:
diff --git a/chrome/browser/search_engines/template_url.h b/chrome/browser/search_engines/template_url.h
index e7cc20b..ff95397 100644
--- a/chrome/browser/search_engines/template_url.h
+++ b/chrome/browser/search_engines/template_url.h
@@ -127,6 +127,12 @@ class TemplateURLRef {
 
     // When searching for an image, the original size of the image.
     gfx::Size image_original_size;
+
+    // If set, ReplaceSearchTerms() will append a param to the TemplateURLRef to
+    // update the search results page incrementally even if that is otherwise
+    // disabled by google.com preferences. See comments on
+    // SearchTermsData::ForceInstantResultsParam().
+    bool force_instant_results;
   };
 
   TemplateURLRef(TemplateURL* owner, Type type);
@@ -253,7 +259,7 @@ class TemplateURLRef {
     GOOGLE_IMAGE_SEARCH_SOURCE,
     GOOGLE_IMAGE_THUMBNAIL,
     GOOGLE_IMAGE_URL,
-    GOOGLE_INSTANT_ENABLED,
+    GOOGLE_FORCE_INSTANT_RESULTS,
     GOOGLE_INSTANT_EXTENDED_ENABLED,
     GOOGLE_NTP_IS_THEMED,
     GOOGLE_OMNIBOX_START_MARGIN,
diff --git a/chrome/browser/ui/search/instant_controller.cc b/chrome/browser/ui/search/instant_controller.cc
index 334d93a..458c5f8 100644
--- a/chrome/browser/ui/search/instant_controller.cc
+++ b/chrome/browser/ui/search/instant_controller.cc
@@ -130,7 +130,7 @@ void InstantController::InstantPageLoadFailed(content::WebContents* contents) {
   // we don't want to redirect and nuke their forward history stack.
   const GURL& current_url = contents->GetURL();
   GURL instant_url = chrome::GetInstantURL(profile(),
-                                           chrome::kDisableStartMargin);
+                                           chrome::kDisableStartMargin, false);
   if (instant_tab_->IsLocal() ||
       !search::MatchesOriginAndPath(instant_url, current_url) ||
       !current_url.ref().empty() ||
diff --git a/chrome/browser/ui/search/instant_ntp_prerenderer.cc b/chrome/browser/ui/search/instant_ntp_prerenderer.cc
index e009b97..fd32a1b 100644
--- a/chrome/browser/ui/search/instant_ntp_prerenderer.cc
+++ b/chrome/browser/ui/search/instant_ntp_prerenderer.cc
@@ -133,7 +133,8 @@ std::string InstantNTPPrerenderer::GetInstantURL() const {
 
   // TODO(kmadhusu): Remove start margin param from chrome::GetInstantURL().
   const GURL instant_url = chrome::GetInstantURL(profile_,
-                                                 chrome::kDisableStartMargin);
+                                                 chrome::kDisableStartMargin,
+                                                 false);
   if (!instant_url.is_valid())
     return GetLocalInstantURL();
 
diff --git a/chrome/test/data/diagnostics/user/Default/Preferences b/chrome/test/data/diagnostics/user/Default/Preferences
index 4f348af..0718051 100644
--- a/chrome/test/data/diagnostics/user/Default/Preferences
+++ b/chrome/test/data/diagnostics/user/Default/Preferences
@@ -22,7 +22,7 @@
       "encodings": "UTF-8",
       "icon_url": "http://www.google.com/favicon.ico",
       "id": "2",
-      "instant_url": "{google:baseURL}webhp?sourceid=chrome-instant&{google:RLZ}{google:instantEnabledParameter}{google:instantExtendedEnabledParameter}{google:ntpIsThemedParameter}{google:omniboxStartMarginParameter}ie={inputEncoding}",
+      "instant_url": "{google:baseURL}webhp?sourceid=chrome-instant&{google:RLZ}{google:forceInstantResults}{google:instantExtendedEnabledParameter}{google:ntpIsThemedParameter}{google:omniboxStartMarginParameter}ie={inputEncoding}",
       "keyword": "google.com",
       "name": "Google",
       "prepopulate_id": "1",
diff --git a/chrome/test/data/page_cycler/cached_data_dir/Default/Preferences b/chrome/test/data/page_cycler/cached_data_dir/Default/Preferences
index 422def0..6b8419f 100644
--- a/chrome/test/data/page_cycler/cached_data_dir/Default/Preferences
+++ b/chrome/test/data/page_cycler/cached_data_dir/Default/Preferences
@@ -34,7 +34,7 @@
       "encodings": "UTF-8",
       "icon_url": "http://www.google.com/favicon.ico",
       "id": "2",
-      "instant_url": "{google:baseURL}webhp?{google:RLZ}sourceid=chrome-instant&{google:instantFieldTrialGroupParameter}ie={inputEncoding}{google:instantEnabledParameter}{searchTerms}",
+      "instant_url": "{google:baseURL}webhp?{google:RLZ}sourceid=chrome-instant&{google:instantFieldTrialGroupParameter}ie={inputEncoding}{google:forceInstantResults}{searchTerms}",
       "keyword": "google.com",
       "name": "Google",
       "prepopulate_id": "1",