Revert 244407 "InstantExtended: remove dead code related to the ..."

trunk/src/chrome/browser/ui/search/search_tab_helper.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/ui/search/search_tab_helper.h"
 
 #include <set>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
@@ skipping 52 matching lines @@
 void RecordCacheableNTPLoadHistogram(bool succeeded) {
   UMA_HISTOGRAM_ENUMERATION("InstantExtended.CacheableNTPLoad",
                             succeeded ? CACHEABLE_NTP_LOAD_SUCCEEDED :
                                 CACHEABLE_NTP_LOAD_FAILED,
                             CACHEABLE_NTP_LOAD_MAX);
 }
 
 bool IsCacheableNTP(const content::WebContents* contents) {
   const content::NavigationEntry* entry =
       contents->GetController().GetLastCommittedEntry();
-  return chrome::NavEntryIsInstantNTP(contents, entry) &&
+  return chrome::ShouldUseCacheableNTP() &&
+      chrome::NavEntryIsInstantNTP(contents, entry) &&
       entry->GetURL() != GURL(chrome::kChromeSearchLocalNtpUrl);
 }
 
 bool IsNTP(const content::WebContents* contents) {
   // We can't use WebContents::GetURL() because that uses the active entry,
   // whereas we want the visible entry.
   const content::NavigationEntry* entry =
       contents->GetController().GetVisibleEntry();
   if (entry && entry->GetVirtualURL() == GURL(chrome::kChromeUINewTabURL))
     return true;
@@ skipping 203 matching lines @@
     const base::string16& /* frame_unique_name */,
     bool is_main_frame,
     const GURL& validated_url,
     int error_code,
     const base::string16& /* error_description */,
     content::RenderViewHost* /* render_view_host */) {
   // If error_code is ERR_ABORTED means that the user has canceled this
   // navigation so it shouldn't be redirected.
   if (is_main_frame &&
       error_code != net::ERR_ABORTED &&
+      chrome::ShouldUseCacheableNTP() &&
       validated_url != GURL(chrome::kChromeSearchLocalNtpUrl) &&
       chrome::IsNTPURL(validated_url, profile())) {
     RedirectToLocalNTP();
     RecordCacheableNTPLoadHistogram(false);
   }
 }
 
 void SearchTabHelper::DidFinishLoad(
     int64 /* frame_id */,
     const GURL&  /* validated_url */,
@@ skipping 285 matching lines @@
 void SearchTabHelper::RedirectToLocalNTP() {
   // Extra parentheses to declare a variable.
   content::NavigationController::LoadURLParams load_params(
       (GURL(chrome::kChromeSearchLocalNtpUrl)));
   load_params.referrer = content::Referrer();
   load_params.transition_type = content::PAGE_TRANSITION_SERVER_REDIRECT;
   // Don't push a history entry.
   load_params.should_replace_current_entry = true;
   web_contents_->GetController().LoadURLWithParams(load_params);
 }