Add "Show saved copy" button in dino page when there's offline copy

components/error_page/renderer/net_error_helper_core.h

Index: components/error_page/renderer/net_error_helper_core.h
diff --git a/components/error_page/renderer/net_error_helper_core.h b/components/error_page/renderer/net_error_helper_core.h
index d5c8930d943d5c4f88809546b1510449b0df8f6f..99c1a136bdca1c56753b2ab35cc70ad6ae8a6c8e 100644
--- a/components/error_page/renderer/net_error_helper_core.h
+++ b/components/error_page/renderer/net_error_helper_core.h
@@ -50,7 +50,8 @@ class NetErrorHelperCore {
     EASTER_EGG,
     SHOW_CACHED_COPY_BUTTON,  // "Google cached copy" button label experiment.
     DIAGNOSE_ERROR,
-    SHOW_SAVED_PAGES_BUTTON,
+    SHOW_OFFLINE_PAGES_BUTTON,  // "Offline pages" experiment.
+    SHOW_OFFLINE_COPY_BUTTON,  // "Offline pages" experiment.
   };
 
   // The Delegate handles all interaction with the RenderView, WebFrame, and
@@ -62,12 +63,13 @@ class NetErrorHelperCore {
         const blink::WebURLError& error,
         bool is_failed_post,
         bool can_show_network_diagnostics_dialog,
-        bool has_offline_pages,
+        int offline_page_status,
         scoped_ptr<ErrorPageParams> params,
         bool* reload_button_shown,
         bool* show_saved_copy_button_shown,
         bool* show_cached_copy_button_shown,
-        bool* show_saved_pages_button_shown,
+        bool* show_offline_pages_button_shown,
+        bool* show_offline_copy_button_shown,
         std::string* html) const = 0;
 
     // Loads the given HTML in the frame for use as an error page.
@@ -84,7 +86,7 @@ class NetErrorHelperCore {
     virtual void UpdateErrorPage(const blink::WebURLError& error,
                                  bool is_failed_post,
                                  bool can_show_network_diagnostics_dialog,
-                                 bool has_offline_pages) = 0;
+                                 int offline_page_status) = 0;
 
     // Fetches an error page and calls into OnErrorPageFetched when done.  Any
     // previous fetch must either be canceled or finished before calling.  Can't
@@ -112,9 +114,14 @@ class NetErrorHelperCore {
     // Run the platform diagnostics too for the specified URL.
     virtual void DiagnoseError(const GURL& page_url) = 0;
 
-    // Shows the UI for offline pages.
+    // Shows all the offline pages that were saved in storage.
     virtual void ShowOfflinePages() = 0;
 
+    // Loads the offline copy of the page that was saved in storage.
+    // Note that this is different from the saved copy in the cache as in
+    // LoadPageFromCache.
+    virtual void LoadOfflineCopy(const GURL& page_url) = 0;
+
    protected:
     virtual ~Delegate() {}
   };
@@ -178,8 +185,8 @@ class NetErrorHelperCore {
                                      const std::string& api_key,
                                      const GURL& search_url);
 
-  // Notifies by the browser whether an offline page exists.
-  void OnSetHasOfflinePages(bool has_offline_pages);
+  // Notifies by the browser about the offline page info.
+  void OnSetOfflinePageInfo(int offline_page_status);
 
   // Notifies |this| that the network's online status changed.
   // Handler for NetworkStateChanged notification from the browser process. If
@@ -292,9 +299,9 @@ class NetErrorHelperCore {
   // in errors.
   Button navigation_from_button_;
 
-  // Whether an offline page exists. This is used to decide if "Show saved
-  // pages" will be provided in certain error page.
-  bool has_offline_pages_;
+  // Status of offline pages. This is used to decide if offline related button
+  // will be provided in certain error page.
+  int offline_page_status_;
 };
 
 }  // namespace error_page