Implement local NTP for fallback.

chrome/browser/instant/search.cc

Index: chrome/browser/instant/search.cc
diff --git a/chrome/browser/instant/search.cc b/chrome/browser/instant/search.cc
index 83c655a09c8ac109965133f487618566e6ffa4bc..7bebf5ff181d8924ea4365e43354a77642f51856 100644
--- a/chrome/browser/instant/search.cc
+++ b/chrome/browser/instant/search.cc
@@ -301,7 +301,8 @@ bool NavEntryIsInstantNTP(const content::WebContents* contents,
   Profile* profile = Profile::FromBrowserContext(contents->GetBrowserContext());
   return IsInstantExtendedAPIEnabled() &&
          IsRenderedInInstantProcess(contents, profile) &&
-         IsInstantURL(entry->GetVirtualURL(), profile) &&
+         (IsInstantURL(entry->GetVirtualURL(), profile) ||
+          entry->GetVirtualURL() == GURL(chrome::kChromeSearchLocalNTPURL)) &&
          GetSearchTermsImpl(contents, entry).empty();
 }
 
@@ -311,7 +312,8 @@ bool ShouldAssignURLToInstantRenderer(const GURL& url, Profile* profile) {
          (url.SchemeIs(chrome::kChromeSearchScheme) ||
           IsInstantURL(url, profile) ||
           (IsInstantExtendedAPIEnabled() &&
-           url == GURL(chrome::kChromeSearchLocalOmniboxPopupURL)));
+          (url == GURL(chrome::kChromeSearchLocalNTPURL) ||
+           url == GURL(chrome::kChromeSearchLocalOmniboxPopupURL))));
 }
 
 void RegisterUserPrefs(PrefRegistrySyncable* registry) {