Adds a basic offline check to InstallableManager.

chrome/browser/installable/installable_logging.h

Index: chrome/browser/installable/installable_logging.h
diff --git a/chrome/browser/installable/installable_logging.h b/chrome/browser/installable/installable_logging.h
index 369afc5fbd4f0010941b7c0e2b3fdab3925ba36a..910121b66ea12d99d1be4f9ce878bcc010c358db 100644
--- a/chrome/browser/installable/installable_logging.h
+++ b/chrome/browser/installable/installable_logging.h
@@ -46,6 +46,7 @@ enum InstallableStatusCode {
   FAILED_TO_CREATE_BANNER,
   URL_NOT_SUPPORTED_FOR_WEBAPK,
   IN_INCOGNITO,
+  NO_SERVICE_WORKER_FETCH_HANDLER,

[dominickn, 2017/03/16 06:21:56]

Nit: SITE_NOT_OFFLINE_CAPABLE ? I think it's best to avoid specifying what we're
exactly checking because the overall intent is to check offline capability.

[piotrs, 2017/03/17 02:21:37]

Done.

   MAX_ERROR_CODE,

[dominickn, 2017/03/16 06:21:56]

You'll need to edit the (giant giant) tools/metrics/histograms/histograms.xml
file to add this value to make sure the histograms backend picks this up (this
enum is used for sending metrics back to us).

[piotrs, 2017/03/17 02:21:37]

Thanks, missed that :) Done.

 };