Don't enforce X-Frame-Options for downloads.

content/browser/frame_host/ancestor_throttle.cc

Index: content/browser/frame_host/ancestor_throttle.cc
diff --git a/content/browser/frame_host/ancestor_throttle.cc b/content/browser/frame_host/ancestor_throttle.cc
index 8f52434d6ed4465089e8e2710a2115d0b4b4531a..0bb5531d20e23f4b1bad4fa1c6b9dcee4503d063 100644
--- a/content/browser/frame_host/ancestor_throttle.cc
+++ b/content/browser/frame_host/ancestor_throttle.cc
@@ -105,6 +105,11 @@ AncestorThrottle::WillProcessResponse() {
   NavigationHandleImpl* handle =
       static_cast<NavigationHandleImpl*>(navigation_handle());
 
+  // Downloads should be exempt from checking for X-Frame-Options, so
+  // proceed if this is a download.
+  if (handle->is_download())
+    return NavigationThrottle::PROCEED;
+
   std::string header_value;
   HeaderDisposition disposition =
       ParseHeader(handle->GetResponseHeaders(), &header_value);