TopSites: filter out non-WebSafe URLs

ios/chrome/browser/history/history_backend_client_impl.cc

Index: ios/chrome/browser/history/history_backend_client_impl.cc
diff --git a/ios/chrome/browser/history/history_backend_client_impl.cc b/ios/chrome/browser/history/history_backend_client_impl.cc
index 4100bce855b43388fb2e3ac046a81367a2755b34..dd43d9088e4f7d70bc651126d1bb9bded84f2093 100644
--- a/ios/chrome/browser/history/history_backend_client_impl.cc
+++ b/ios/chrome/browser/history/history_backend_client_impl.cc
@@ -48,3 +48,7 @@ void HistoryBackendClientImpl::GetBookmarks(
 bool HistoryBackendClientImpl::ShouldReportDatabaseError() {
   return false;
 }
+
+bool HistoryBackendClientImpl::IsWebSafe(const GURL& url) {
+  return true;

[Marc Treib, 2016/05/02 15:29:44]

On non-iOS, we check this via
content::ChildProcessSecurityPolicy::IsWebSafeScheme, but I couldn't find
anything equivalent on iOS. Do you know of something?

[sdefresne, 2016/05/03 11:18:50]

I think we do not have a dedicated method to do that. We usually just check
whether scheme is http or https (which are the two safe scheme among the few iOS
supports), i.e.:

return url.SchemeIs(url::kHttpScheme) || url.SchemeIs(url::kHttpsScheme);

[Marc Treib, 2016/05/03 11:51:17]

GURL even has a SchemeIsHTTPOrHTTPS() method :)
Are these really the only supported schemes though? I'd have expected at least
FTP too?

[sdefresne, 2016/05/03 12:03:39]

No, Chrome on iOS does not support ftp:, nor file: schemes. It supports chrome:,
http:, https:, data: and javascript: IIRC.

[Marc Treib, 2016/05/03 12:15:10]

Alright, thanks for the explanation!
I suppose "data:" could also be considered web-safe, but I don't see that ever
coming up (and even if it did, it doesn't seem useful for TopSites).

+}