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

chrome/browser/android/tab_android.h

Index: chrome/browser/android/tab_android.h
diff --git a/chrome/browser/android/tab_android.h b/chrome/browser/android/tab_android.h
index ccf65d0149b942fb22eb1518e3c650dfafd018c8..af0bd53759a244c5c10bd1c08828416ce9154cdb 100644
--- a/chrome/browser/android/tab_android.h
+++ b/chrome/browser/android/tab_android.h
@@ -127,7 +127,9 @@ class TabAndroid : public CoreTabHelperDelegate,
       content::NavigationController::LoadURLParams* load_url_params);
 
   bool HasOfflinePages() const;
+  bool HasOfflineCopyForCurrentPage() const;
   void ShowOfflinePages();
+  void LoadOfflineCopy(const GURL& url);
 
   // Overridden from CoreTabHelperDelegate:
   void SwapTabContents(content::WebContents* old_contents,
@@ -240,6 +242,8 @@ class TabAndroid : public CoreTabHelperDelegate,
  private:
   prerender::PrerenderManager* GetPrerenderManager() const;
 
+  int64_t GetBookmarkIdHelper(bool only_editable) const;
+
   const offline_pages::OfflinePageItem* GetOfflinePage(const GURL& url) const;
 
   JavaObjectWeakGlobalRef weak_java_tab_;