Implement local NTP for fallback.

chrome/browser/instant/search.cc

 // Copyright 2012 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/instant/search.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
@@ skipping 283 matching lines @@
 }
 
 bool NavEntryIsInstantNTP(const content::WebContents* contents,
                           const content::NavigationEntry* entry) {
   if (!contents || !entry)
     return false;
 
   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();
 }
 
 bool ShouldAssignURLToInstantRenderer(const GURL& url, Profile* profile) {
   return url.is_valid() &&
          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) {
   registry->RegisterBooleanPref(prefs::kInstantConfirmDialogShown, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
   registry->RegisterBooleanPref(prefs::kInstantEnabled, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
   // This default is overridden by SetInstantExtendedPrefDefault().
   registry->RegisterBooleanPref(prefs::kInstantExtendedEnabled, false,
                                 PrefRegistrySyncable::SYNCABLE_PREF);
@@ skipping 191 matching lines @@
   GURL::Replacements replacements;
   replacements.SetSchemeStr(search_scheme);
   replacements.SetHostStr(search_host);
   replacements.SetPortStr(search_port);
   replacements.SetPathStr(search_path);
   return instant_url.ReplaceComponents(replacements);
 }
 
 }  // namespace search
 }  // namespace chrome