[Offline pages] Add new Error page failure status inside the MHTML archiver and update correspondin…

components/offline_pages/core/offline_page_archiver.h

Index: components/offline_pages/core/offline_page_archiver.h
diff --git a/components/offline_pages/core/offline_page_archiver.h b/components/offline_pages/core/offline_page_archiver.h
index 31f2d337c742086182234949d21d9a3c94a848ed..112419f5493d0d6b8e64a555fa11558c1332cfc9 100644
--- a/components/offline_pages/core/offline_page_archiver.h
+++ b/components/offline_pages/core/offline_page_archiver.h
@@ -50,6 +50,7 @@ class OfflinePageArchiver {
     ERROR_ARCHIVE_CREATION_FAILED,  // Creation of archive failed.
     ERROR_SECURITY_CERTIFICATE,     // Page was loaded on secure connection, but
                                     // there was a security error.
+    ERROR_PAGE,                     // We detected an error page.

[fgorski, 2017/04/10 21:19:17]

ERROR_WRONG_PAGE_TYPE
(you mention that both error pages and interstitial pages qualify)

[chili, 2017/04/11 20:40:16]

Done.

   };
 
   // Describes the parameters to control how to create an archive.