Fall back to local page if online NTP fails to load.

chrome/browser/ui/search/instant_page.h

Index: chrome/browser/ui/search/instant_page.h
diff --git a/chrome/browser/ui/search/instant_page.h b/chrome/browser/ui/search/instant_page.h
index 93c9cc8a9b7fc174ba368e85d9dd71d5467dce9c..79dd63231364be3ea8911a946ff1d764cfe788c2 100644
--- a/chrome/browser/ui/search/instant_page.h
+++ b/chrome/browser/ui/search/instant_page.h
@@ -19,6 +19,8 @@ class GURL;
 
 namespace content {
 class WebContents;
+struct FrameNavigateParams;
+struct LoadCommittedDetails;
 }
 
 namespace gfx {
@@ -91,6 +93,9 @@ class InstantPage : public content::WebContentsObserver {
     // Called when the SearchBox wants to undo all Most Visited deletions.
     virtual void UndoAllMostVisitedDeletions() = 0;
 
+    // Called when the preloaded NTP is ready for display.
+    virtual void InstantPageLoadFailed(content::WebContents* contents) = 0;
+
    protected:
     virtual ~Delegate();
   };
@@ -211,6 +216,17 @@ class InstantPage : public content::WebContentsObserver {
       const GURL& url,
       content::PageTransition transition_type,
       content::RenderViewHost* render_view_host) OVERRIDE;
+  virtual void DidNavigateMainFrame(
+      const content::LoadCommittedDetails& details,
+      const content::FrameNavigateParams& params) OVERRIDE;
+

[samarth, 2013/05/01 06:26:47]

nit: extra empty line

[David Black, 2013/05/02 00:49:45]

Done.

+  virtual void DidFailProvisionalLoad(
+      int64 frame_id,
+      bool is_main_frame,
+      const GURL& validated_url,
+      int error_code,
+      const string16& error_description,
+      content::RenderViewHost* render_view_host) OVERRIDE;
 
   void OnSetSuggestions(int page_id,
                         const std::vector<InstantSuggestion>& suggestions);