[New Tab Page] Change the mechanism to intercept online NTP errors

chrome/browser/ui/search/search_tab_helper.cc

Index: chrome/browser/ui/search/search_tab_helper.cc
diff --git a/chrome/browser/ui/search/search_tab_helper.cc b/chrome/browser/ui/search/search_tab_helper.cc
index b610cee66d12737eae90c302ed706a810bbaeaf9..b0768e70df66f038296f8d1fbb64e6218e1ce08b 100644
--- a/chrome/browser/ui/search/search_tab_helper.cc
+++ b/chrome/browser/ui/search/search_tab_helper.cc
@@ -55,20 +55,6 @@ DEFINE_WEB_CONTENTS_USER_DATA_KEY(SearchTabHelper);
 
 namespace {
 
-// For reporting Cacheable NTP navigations.
-enum CacheableNTPLoad {
-  CACHEABLE_NTP_LOAD_FAILED = 0,
-  CACHEABLE_NTP_LOAD_SUCCEEDED = 1,
-  CACHEABLE_NTP_LOAD_MAX = 2
-};
-
-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();
@@ -310,12 +296,9 @@ void SearchTabHelper::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
   if (IsCacheableNTP(web_contents_)) {
-    if (details.http_status_code == 204 || details.http_status_code >= 400) {
-      RedirectToLocalNTP();
-      RecordCacheableNTPLoadHistogram(false);
-      return;
-    }
-    RecordCacheableNTPLoadHistogram(true);
+    UMA_HISTOGRAM_ENUMERATION("InstantExtended.CacheableNTPLoad",
+                              chrome::CACHEABLE_NTP_LOAD_SUCCEEDED,
+                              chrome::CACHEABLE_NTP_LOAD_MAX);
   }
 
   // Always set the title on the new tab page to be the one from our UI
@@ -337,21 +320,6 @@ void SearchTabHelper::DidNavigateMainFrame(
   }
 }
 
-void SearchTabHelper::DidFailProvisionalLoad(
-    content::RenderFrameHost* render_frame_host,
-    const GURL& validated_url,
-    int error_code,
-    const base::string16& /* error_description */) {
-  // If error_code is ERR_ABORTED means that the user has canceled this
-  // navigation so it shouldn't be redirected.
-  if (!render_frame_host->GetParent() && error_code != net::ERR_ABORTED &&
-      validated_url != GURL(chrome::kChromeSearchLocalNtpUrl) &&
-      chrome::IsNTPURL(validated_url, profile())) {
-    RedirectToLocalNTP();
-    RecordCacheableNTPLoadHistogram(false);
-  }
-}
-
 void SearchTabHelper::DidFinishLoad(content::RenderFrameHost* render_frame_host,
                                     const GURL& /* validated_url */) {
   if (!render_frame_host->GetParent()) {
@@ -618,17 +586,6 @@ Profile* SearchTabHelper::profile() const {
   return Profile::FromBrowserContext(web_contents_->GetBrowserContext());
 }
 
-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 = ui::PAGE_TRANSITION_SERVER_REDIRECT;
-  // Don't push a history entry.
-  load_params.should_replace_current_entry = true;
-  web_contents_->GetController().LoadURLWithParams(load_params);
-}
-
 bool SearchTabHelper::IsInputInProgress() const {
   OmniboxView* omnibox = GetOmniboxView();
   return !model_.mode().is_ntp() && omnibox &&