Remove LOAD_SUB_FRAME load flag.

It's not used in net, and net/ knowing about frames is a layering
violation.  External consumers that depended on it now use the
corresponding ResourceType instead.

BUG=426442

Review URL: https://codereview.chromium.org/1134733004

Cr-Commit-Position: refs/heads/master@{#330370}
diff --git a/chrome/browser/net/chrome_network_delegate.cc b/chrome/browser/net/chrome_network_delegate.cc
index 9348cef..4953a72 100644
--- a/chrome/browser/net/chrome_network_delegate.cc
+++ b/chrome/browser/net/chrome_network_delegate.cc
@@ -377,9 +377,13 @@
   // TODO(joaodasilva): This prevents extensions from seeing URLs that are
   // blocked. However, an extension might redirect the request to another URL,
   // which is not blocked.
+
+  const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
   int error = net::ERR_BLOCKED_BY_ADMINISTRATOR;
-  if (url_blacklist_manager_ &&
-      url_blacklist_manager_->IsRequestBlocked(*request, &error)) {
+  if (info && content::IsResourceTypeFrame(info->GetResourceType()) &&
+      url_blacklist_manager_ &&
+      url_blacklist_manager_->ShouldBlockRequestForFrame(
+          request->url(), &error)) {
     // URL access blocked by policy.
     request->net_log().AddEvent(
         net::NetLog::TYPE_CHROME_POLICY_ABORTED_REQUEST,