Show generic network error interstitial for 4xx / 5xx errors that do not

have any content

Currently only a small subset of 4xx and 5xx HTTP errors show a net error
interstitial when the server responds with no content. This CL adds 
generic messaging for the other cases.

Bug: 632778
Change-Id: If39bf0ba1c89ac5e2b5a27f5973e1accc25dc0fa
Reviewed-on: https://chromium-review.googlesource.com/685674Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Edward Jung <edwardjung@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505337}

components/error_page/common/localized_error.cc

@@ -388,6 +388,14 @@ const LocalizedErrorMap http_error_options[] = {
     },
 };
 
+const LocalizedErrorMap generic_4xx_5xx_error = {
+    0,
+    IDS_ERRORPAGES_HEADING_PAGE_NOT_WORKING,
+    IDS_ERRORPAGES_SUMMARY_CONTACT_SITE_OWNER,
+    SUGGEST_NONE,
+    SHOW_BUTTON_RELOAD,
+};
+
 const LocalizedErrorMap dns_probe_error_options[] = {
   {error_page::DNS_PROBE_POSSIBLE,
    IDS_ERRORPAGES_HEADING_NOT_AVAILABLE,
@@ -452,9 +460,12 @@ const LocalizedErrorMap* LookupErrorMap(const std::string& error_domain,
                                arraysize(net_error_options),
                                error_code);
   } else if (error_domain == Error::kHttpErrorDomain) {
-    return FindErrorMapInArray(http_error_options,
-                               arraysize(http_error_options),
-                               error_code);
+    const LocalizedErrorMap* map = FindErrorMapInArray(
+        http_error_options, arraysize(http_error_options), error_code);
+    // Handle miscellaneous 400/500 errors.
+    return !map && error_code >= 400 && error_code < 600
+               ? &generic_4xx_5xx_error
+               : map;
   } else if (error_domain == Error::kDnsProbeErrorDomain) {
     const LocalizedErrorMap* map =
         FindErrorMapInArray(dns_probe_error_options,

components/error_page_strings.grdp

@@ -218,7 +218,9 @@
   <message name="IDS_ERRORPAGES_HEADING_PAGE_NOT_WORKING" desc="Heading in the error page for HTTP 5xx errors, which are considered to be server side errors. Also used for bad responses.">
     This page isn’t working
   </message>
-
+  <message name="IDS_ERRORPAGES_SUMMARY_CONTACT_SITE_OWNER" desc="Generic suggestion for when the server returns a HTTP 4xx or 5xx error asking users to contact the site owner.">
+    If the problem continues, contact the site owner.
+  </message>
   <message name="IDS_ERRORPAGES_SUMMARY_WEBSITE_CANNOT_HANDLE_REQUEST" desc="Summary in the error page when the server returns a 501 or 505.">
     <ph name="HOST_NAME">&lt;strong jscontent="hostName"&gt;&lt;/strong&gt;<ex>www.whatever.com</ex></ph> is currently unable to handle this request.
   </message>