PlzNavigate: add dump to understand pdf navigation cancellation

content/browser/frame_host/navigation_request.cc

Index: content/browser/frame_host/navigation_request.cc
diff --git a/content/browser/frame_host/navigation_request.cc b/content/browser/frame_host/navigation_request.cc
index 4036937d35a7121727d7308a8b702d132d10d4f5..46dfbc5d8cb8be8542fb66fb7f3ad471c9fd0a38 100644
--- a/content/browser/frame_host/navigation_request.cc
+++ b/content/browser/frame_host/navigation_request.cc
@@ -610,6 +610,11 @@ void NavigationRequest::OnRequestFailed(bool has_stale_copy_in_cache,
 
   // If the request was canceled by the user do not show an error page.
   if (net_error == net::ERR_ABORTED) {
+    // TODO(clamy): Remove this once we understand the root cause of
+    // crbug.com/709771.
+    if (common_params_.url.spec().find(".pdf") != std::string::npos)

[nasko, 2017/04/17 21:30:05]

Shouldn't this be searching only at the end of the path component? Otherwise
anything in the query string or the domain part can trip it, which I think is a
bit too lax.

[clamy, 2017/04/18 15:29:55]

Done.

+      base::debug::DumpWithoutCrashing();
+
     frame_tree_node_->ResetNavigationRequest(false, true);
     return;
   }