Treat external protocols as ABORTED with PlzNavigate

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index b34eca2b8379e722f58289572ff7ca06bd150a76..ca487a74d5a18353dd5d50beeaae248f4660920d 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -164,6 +164,10 @@ NavigationHandleImpl::~NavigationHandleImpl() {
         base::Bind(&NotifyAbandonedTransferNavigation, GetGlobalRequestID()));
   }
 
+  if (!GetContentClient()->browser()->IsHandledURL(url_)) {

[jam, 2017/03/24 14:49:49]

if this was handled by the navigation interceptor in components/, then it should
have got this error code then. Why does it have to be set again? Ted has a
theory that maybe it's being reset when the fallback url is requested? Can you
try loading the fallback url in java on a post task to see if it fixes this?

[wychen, 2017/03/24 15:33:55]

This is obviously the wrong place to inject the error. I'll look into it.
BTW, what do you mean by a post task?

+    net_error_code_ = net::ERR_ABORTED;
+  }
+
   if (!IsRendererDebugURL(url_))
     GetDelegate()->DidFinishNavigation(this);