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

chrome/browser/ui/search/search_tab_helper.h

 // 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.
 
 #ifndef CHROME_BROWSER_UI_SEARCH_SEARCH_TAB_HELPER_H_
 #define CHROME_BROWSER_UI_SEARCH_SEARCH_TAB_HELPER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 135 matching lines @@
   explicit SearchTabHelper(content::WebContents* web_contents);
 
   // Overridden from contents::WebContentsObserver:
   void RenderViewCreated(content::RenderViewHost* render_view_host) override;
   void DidStartNavigationToPendingEntry(
       const GURL& url,
       content::NavigationController::ReloadType reload_type) override;
   void DidNavigateMainFrame(
       const content::LoadCommittedDetails& details,
       const content::FrameNavigateParams& params) override;
-  void DidFailProvisionalLoad(content::RenderFrameHost* render_frame_host,
-                              const GURL& validated_url,
-                              int error_code,
-                              const base::string16& error_description) override;
   void DidFinishLoad(content::RenderFrameHost* render_frame_host,
                      const GURL& validated_url) override;
   void NavigationEntryCommitted(
       const content::LoadCommittedDetails& load_details) override;
 
   // Overridden from SearchIPCRouter::Delegate:
   void OnInstantSupportDetermined(bool supports_instant) override;
   void OnSetVoiceSearchSupport(bool supports_voice_search) override;
   void FocusOmnibox(OmniboxFocusState state) override;
   void NavigateToURL(const GURL& url,
@@ skipping 27 matching lines @@
   // Tells the renderer to determine if the page supports the Instant API, which
   // results in a call to OnInstantSupportDetermined() when the reply is
   // received.
   void DetermineIfPageSupportsInstant();
 
   // Used by unit tests.
   SearchIPCRouter& ipc_router() { return ipc_router_; }
 
   Profile* profile() const;
 
-  // Helper function to navigate the given contents to the local fallback
-  // Instant URL and trim the history correctly.
-  void RedirectToLocalNTP();
-
   // Returns whether input is in progress, i.e. if the omnibox has focus and the
   // active tab is in mode SEARCH_SUGGESTIONS.
   bool IsInputInProgress() const;
 
   // Returns the OmniboxView for |web_contents_| or NULL if not available.
   OmniboxView* GetOmniboxView() const;
 
   typedef bool (*OmniboxHasFocusFn)(OmniboxView*);
 
   void set_omnibox_has_focus_fn(OmniboxHasFocusFn fn) {
@@ skipping 17 matching lines @@
   SearchTabHelperDelegate* delegate_;
 
   // Function to check if the omnibox has focus. Tests use this to modify the
   // default behavior.
   OmniboxHasFocusFn omnibox_has_focus_fn_;
 
   DISALLOW_COPY_AND_ASSIGN(SearchTabHelper);
 };
 
 #endif  // CHROME_BROWSER_UI_SEARCH_SEARCH_TAB_HELPER_H_