Adds a basic offline check to InstallableManager.

chrome/browser/installable/installable_logging.cc

Index: chrome/browser/installable/installable_logging.cc
diff --git a/chrome/browser/installable/installable_logging.cc b/chrome/browser/installable/installable_logging.cc
index 6f0cdc4234663866ee29a6e93d5e3edd60658f70..926dd2a3d6beadadfe3fbd6c43e79086faa210f4 100644
--- a/chrome/browser/installable/installable_logging.cc
+++ b/chrome/browser/installable/installable_logging.cc
@@ -64,7 +64,7 @@ static const char kUrlNotSupportedForWebApkMessage[] =
     "a URL in the web manifest contains a username, password, or port";
 static const char kInIncognitoMessage[] =
     "the page is loaded in an incognito window";
-
+static const char kNotOfflineCapable[] = "the page does not work offline";
 }  // namespace
 
 void LogErrorToConsole(content::WebContents* web_contents,
@@ -151,6 +151,9 @@ void LogErrorToConsole(content::WebContents* web_contents,
     case IN_INCOGNITO:
       pattern = kInIncognitoMessage;
       break;
+    case NOT_OFFLINE_CAPABLE:
+      pattern = kNotOfflineCapable;
+      break;
   }
 
   if (!pattern)